xref: /linux/drivers/target/target_core_pr.c (revision 7c43185138cf523b0810ffd2c9e18e2ecb356730)
1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * Copyright (c) 2009, 2010 Rising Tide Systems
8  * Copyright (c) 2009, 2010 Linux-iSCSI.org
9  *
10  * Nicholas A. Bellinger <nab@kernel.org>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25  *
26  ******************************************************************************/
27 
28 #include <linux/version.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/list.h>
32 #include <scsi/scsi.h>
33 #include <scsi/scsi_cmnd.h>
34 #include <asm/unaligned.h>
35 
36 #include <target/target_core_base.h>
37 #include <target/target_core_device.h>
38 #include <target/target_core_tmr.h>
39 #include <target/target_core_tpg.h>
40 #include <target/target_core_transport.h>
41 #include <target/target_core_fabric_ops.h>
42 #include <target/target_core_configfs.h>
43 
44 #include "target_core_hba.h"
45 #include "target_core_pr.h"
46 #include "target_core_ua.h"
47 
48 /*
49  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
50  */
51 struct pr_transport_id_holder {
52 	int dest_local_nexus;
53 	struct t10_pr_registration *dest_pr_reg;
54 	struct se_portal_group *dest_tpg;
55 	struct se_node_acl *dest_node_acl;
56 	struct se_dev_entry *dest_se_deve;
57 	struct list_head dest_list;
58 };
59 
60 int core_pr_dump_initiator_port(
61 	struct t10_pr_registration *pr_reg,
62 	char *buf,
63 	u32 size)
64 {
65 	if (!pr_reg->isid_present_at_reg)
66 		return 0;
67 
68 	snprintf(buf, size, ",i,0x%s", &pr_reg->pr_reg_isid[0]);
69 	return 1;
70 }
71 
72 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
73 			struct t10_pr_registration *, int);
74 
75 static int core_scsi2_reservation_seq_non_holder(
76 	struct se_cmd *cmd,
77 	unsigned char *cdb,
78 	u32 pr_reg_type)
79 {
80 	switch (cdb[0]) {
81 	case INQUIRY:
82 	case RELEASE:
83 	case RELEASE_10:
84 		return 0;
85 	default:
86 		return 1;
87 	}
88 
89 	return 1;
90 }
91 
92 static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
93 {
94 	struct se_device *dev = cmd->se_dev;
95 	struct se_session *sess = cmd->se_sess;
96 	int ret;
97 
98 	if (!sess)
99 		return 0;
100 
101 	spin_lock(&dev->dev_reservation_lock);
102 	if (!dev->dev_reserved_node_acl || !sess) {
103 		spin_unlock(&dev->dev_reservation_lock);
104 		return 0;
105 	}
106 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
107 		spin_unlock(&dev->dev_reservation_lock);
108 		return -EINVAL;
109 	}
110 	if (!(dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID)) {
111 		spin_unlock(&dev->dev_reservation_lock);
112 		return 0;
113 	}
114 	ret = (dev->dev_res_bin_isid == sess->sess_bin_isid) ? 0 : -EINVAL;
115 	spin_unlock(&dev->dev_reservation_lock);
116 
117 	return ret;
118 }
119 
120 static int core_scsi2_reservation_release(struct se_cmd *cmd)
121 {
122 	struct se_device *dev = cmd->se_dev;
123 	struct se_session *sess = cmd->se_sess;
124 	struct se_portal_group *tpg = sess->se_tpg;
125 
126 	if (!sess || !tpg)
127 		return 0;
128 
129 	spin_lock(&dev->dev_reservation_lock);
130 	if (!dev->dev_reserved_node_acl || !sess) {
131 		spin_unlock(&dev->dev_reservation_lock);
132 		return 0;
133 	}
134 
135 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
136 		spin_unlock(&dev->dev_reservation_lock);
137 		return 0;
138 	}
139 	dev->dev_reserved_node_acl = NULL;
140 	dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
141 	if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {
142 		dev->dev_res_bin_isid = 0;
143 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS_WITH_ISID;
144 	}
145 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
146 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
147 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
148 		sess->se_node_acl->initiatorname);
149 	spin_unlock(&dev->dev_reservation_lock);
150 
151 	return 0;
152 }
153 
154 static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
155 {
156 	struct se_device *dev = cmd->se_dev;
157 	struct se_session *sess = cmd->se_sess;
158 	struct se_portal_group *tpg = sess->se_tpg;
159 
160 	if ((cmd->t_task_cdb[1] & 0x01) &&
161 	    (cmd->t_task_cdb[1] & 0x02)) {
162 		pr_err("LongIO and Obselete Bits set, returning"
163 				" ILLEGAL_REQUEST\n");
164 		return PYX_TRANSPORT_ILLEGAL_REQUEST;
165 	}
166 	/*
167 	 * This is currently the case for target_core_mod passthrough struct se_cmd
168 	 * ops
169 	 */
170 	if (!sess || !tpg)
171 		return 0;
172 
173 	spin_lock(&dev->dev_reservation_lock);
174 	if (dev->dev_reserved_node_acl &&
175 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
176 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
177 			tpg->se_tpg_tfo->get_fabric_name());
178 		pr_err("Original reserver LUN: %u %s\n",
179 			cmd->se_lun->unpacked_lun,
180 			dev->dev_reserved_node_acl->initiatorname);
181 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
182 			" from %s \n", cmd->se_lun->unpacked_lun,
183 			cmd->se_deve->mapped_lun,
184 			sess->se_node_acl->initiatorname);
185 		spin_unlock(&dev->dev_reservation_lock);
186 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
187 	}
188 
189 	dev->dev_reserved_node_acl = sess->se_node_acl;
190 	dev->dev_flags |= DF_SPC2_RESERVATIONS;
191 	if (sess->sess_bin_isid != 0) {
192 		dev->dev_res_bin_isid = sess->sess_bin_isid;
193 		dev->dev_flags |= DF_SPC2_RESERVATIONS_WITH_ISID;
194 	}
195 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
196 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
197 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
198 		sess->se_node_acl->initiatorname);
199 	spin_unlock(&dev->dev_reservation_lock);
200 
201 	return 0;
202 }
203 
204 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
205 					struct se_node_acl *, struct se_session *);
206 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
207 
208 /*
209  * Setup in target_core_transport.c:transport_generic_cmd_sequencer()
210  * and called via struct se_cmd->transport_emulate_cdb() in TCM processing
211  * thread context.
212  */
213 int core_scsi2_emulate_crh(struct se_cmd *cmd)
214 {
215 	struct se_session *se_sess = cmd->se_sess;
216 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
217 	struct t10_pr_registration *pr_reg;
218 	struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
219 	unsigned char *cdb = &cmd->t_task_cdb[0];
220 	int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
221 	int conflict = 0;
222 
223 	if (!se_sess)
224 		return 0;
225 
226 	if (!crh)
227 		goto after_crh;
228 
229 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
230 			se_sess);
231 	if (pr_reg) {
232 		/*
233 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
234 		 * behavior
235 		 *
236 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
237 		 * status, but no reservation shall be established and the
238 		 * persistent reservation shall not be changed, if the command
239 		 * is received from a) and b) below.
240 		 *
241 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
242 		 * status, but the persistent reservation shall not be released,
243 		 * if the command is received from a) and b)
244 		 *
245 		 * a) An I_T nexus that is a persistent reservation holder; or
246 		 * b) An I_T nexus that is registered if a registrants only or
247 		 *    all registrants type persistent reservation is present.
248 		 *
249 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
250 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
251 		 * as defined in SPC-2.
252 		 */
253 		if (pr_reg->pr_res_holder) {
254 			core_scsi3_put_pr_reg(pr_reg);
255 			return 0;
256 		}
257 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
258 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
259 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
260 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
261 			core_scsi3_put_pr_reg(pr_reg);
262 			return 0;
263 		}
264 		core_scsi3_put_pr_reg(pr_reg);
265 		conflict = 1;
266 	} else {
267 		/*
268 		 * Following spc2r20 5.5.1 Reservations overview:
269 		 *
270 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
271 		 * command with the REGISTER or the REGISTER AND IGNORE
272 		 * EXISTING KEY service action and is still registered by any
273 		 * initiator, all RESERVE commands and all RELEASE commands
274 		 * regardless of initiator shall conflict and shall terminate
275 		 * with a RESERVATION CONFLICT status.
276 		 */
277 		spin_lock(&pr_tmpl->registration_lock);
278 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
279 		spin_unlock(&pr_tmpl->registration_lock);
280 	}
281 
282 	if (conflict) {
283 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
284 			" while active SPC-3 registrations exist,"
285 			" returning RESERVATION_CONFLICT\n");
286 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
287 	}
288 
289 after_crh:
290 	if ((cdb[0] == RESERVE) || (cdb[0] == RESERVE_10))
291 		return core_scsi2_reservation_reserve(cmd);
292 	else if ((cdb[0] == RELEASE) || (cdb[0] == RELEASE_10))
293 		return core_scsi2_reservation_release(cmd);
294 	else
295 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
296 }
297 
298 /*
299  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
300  *
301  * This function is called by those initiator ports who are *NOT*
302  * the active PR reservation holder when a reservation is present.
303  */
304 static int core_scsi3_pr_seq_non_holder(
305 	struct se_cmd *cmd,
306 	unsigned char *cdb,
307 	u32 pr_reg_type)
308 {
309 	struct se_dev_entry *se_deve;
310 	struct se_session *se_sess = cmd->se_sess;
311 	int other_cdb = 0, ignore_reg;
312 	int registered_nexus = 0, ret = 1; /* Conflict by default */
313 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
314 	int we = 0; /* Write Exclusive */
315 	int legacy = 0; /* Act like a legacy device and return
316 			 * RESERVATION CONFLICT on some CDBs */
317 	/*
318 	 * A legacy SPC-2 reservation is being held.
319 	 */
320 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
321 		return core_scsi2_reservation_seq_non_holder(cmd,
322 					cdb, pr_reg_type);
323 
324 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
325 	/*
326 	 * Determine if the registration should be ignored due to
327 	 * non-matching ISIDs in core_scsi3_pr_reservation_check().
328 	 */
329 	ignore_reg = (pr_reg_type & 0x80000000);
330 	if (ignore_reg)
331 		pr_reg_type &= ~0x80000000;
332 
333 	switch (pr_reg_type) {
334 	case PR_TYPE_WRITE_EXCLUSIVE:
335 		we = 1;
336 	case PR_TYPE_EXCLUSIVE_ACCESS:
337 		/*
338 		 * Some commands are only allowed for the persistent reservation
339 		 * holder.
340 		 */
341 		if ((se_deve->def_pr_registered) && !(ignore_reg))
342 			registered_nexus = 1;
343 		break;
344 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
345 		we = 1;
346 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
347 		/*
348 		 * Some commands are only allowed for registered I_T Nexuses.
349 		 */
350 		reg_only = 1;
351 		if ((se_deve->def_pr_registered) && !(ignore_reg))
352 			registered_nexus = 1;
353 		break;
354 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
355 		we = 1;
356 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
357 		/*
358 		 * Each registered I_T Nexus is a reservation holder.
359 		 */
360 		all_reg = 1;
361 		if ((se_deve->def_pr_registered) && !(ignore_reg))
362 			registered_nexus = 1;
363 		break;
364 	default:
365 		return -EINVAL;
366 	}
367 	/*
368 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
369 	 */
370 	switch (cdb[0]) {
371 	case SECURITY_PROTOCOL_IN:
372 		if (registered_nexus)
373 			return 0;
374 		ret = (we) ? 0 : 1;
375 		break;
376 	case MODE_SENSE:
377 	case MODE_SENSE_10:
378 	case READ_ATTRIBUTE:
379 	case READ_BUFFER:
380 	case RECEIVE_DIAGNOSTIC:
381 		if (legacy) {
382 			ret = 1;
383 			break;
384 		}
385 		if (registered_nexus) {
386 			ret = 0;
387 			break;
388 		}
389 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
390 		break;
391 	case PERSISTENT_RESERVE_OUT:
392 		/*
393 		 * This follows PERSISTENT_RESERVE_OUT service actions that
394 		 * are allowed in the presence of various reservations.
395 		 * See spc4r17, table 46
396 		 */
397 		switch (cdb[1] & 0x1f) {
398 		case PRO_CLEAR:
399 		case PRO_PREEMPT:
400 		case PRO_PREEMPT_AND_ABORT:
401 			ret = (registered_nexus) ? 0 : 1;
402 			break;
403 		case PRO_REGISTER:
404 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
405 			ret = 0;
406 			break;
407 		case PRO_REGISTER_AND_MOVE:
408 		case PRO_RESERVE:
409 			ret = 1;
410 			break;
411 		case PRO_RELEASE:
412 			ret = (registered_nexus) ? 0 : 1;
413 			break;
414 		default:
415 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
416 				" action: 0x%02x\n", cdb[1] & 0x1f);
417 			return -EINVAL;
418 		}
419 		break;
420 	case RELEASE:
421 	case RELEASE_10:
422 		/* Handled by CRH=1 in core_scsi2_emulate_crh() */
423 		ret = 0;
424 		break;
425 	case RESERVE:
426 	case RESERVE_10:
427 		/* Handled by CRH=1 in core_scsi2_emulate_crh() */
428 		ret = 0;
429 		break;
430 	case TEST_UNIT_READY:
431 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
432 		break;
433 	case MAINTENANCE_IN:
434 		switch (cdb[1] & 0x1f) {
435 		case MI_MANAGEMENT_PROTOCOL_IN:
436 			if (registered_nexus) {
437 				ret = 0;
438 				break;
439 			}
440 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
441 			break;
442 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
443 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
444 			if (legacy) {
445 				ret = 1;
446 				break;
447 			}
448 			if (registered_nexus) {
449 				ret = 0;
450 				break;
451 			}
452 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
453 			break;
454 		case MI_REPORT_ALIASES:
455 		case MI_REPORT_IDENTIFYING_INFORMATION:
456 		case MI_REPORT_PRIORITY:
457 		case MI_REPORT_TARGET_PGS:
458 		case MI_REPORT_TIMESTAMP:
459 			ret = 0; /* Allowed */
460 			break;
461 		default:
462 			pr_err("Unknown MI Service Action: 0x%02x\n",
463 				(cdb[1] & 0x1f));
464 			return -EINVAL;
465 		}
466 		break;
467 	case ACCESS_CONTROL_IN:
468 	case ACCESS_CONTROL_OUT:
469 	case INQUIRY:
470 	case LOG_SENSE:
471 	case READ_MEDIA_SERIAL_NUMBER:
472 	case REPORT_LUNS:
473 	case REQUEST_SENSE:
474 		ret = 0; /*/ Allowed CDBs */
475 		break;
476 	default:
477 		other_cdb = 1;
478 		break;
479 	}
480 	/*
481 	 * Case where the CDB is explicitly allowed in the above switch
482 	 * statement.
483 	 */
484 	if (!ret && !other_cdb) {
485 #if 0
486 		pr_debug("Allowing explict CDB: 0x%02x for %s"
487 			" reservation holder\n", cdb[0],
488 			core_scsi3_pr_dump_type(pr_reg_type));
489 #endif
490 		return ret;
491 	}
492 	/*
493 	 * Check if write exclusive initiator ports *NOT* holding the
494 	 * WRITE_EXCLUSIVE_* reservation.
495 	 */
496 	if ((we) && !(registered_nexus)) {
497 		if (cmd->data_direction == DMA_TO_DEVICE) {
498 			/*
499 			 * Conflict for write exclusive
500 			 */
501 			pr_debug("%s Conflict for unregistered nexus"
502 				" %s CDB: 0x%02x to %s reservation\n",
503 				transport_dump_cmd_direction(cmd),
504 				se_sess->se_node_acl->initiatorname, cdb[0],
505 				core_scsi3_pr_dump_type(pr_reg_type));
506 			return 1;
507 		} else {
508 			/*
509 			 * Allow non WRITE CDBs for all Write Exclusive
510 			 * PR TYPEs to pass for registered and
511 			 * non-registered_nexuxes NOT holding the reservation.
512 			 *
513 			 * We only make noise for the unregisterd nexuses,
514 			 * as we expect registered non-reservation holding
515 			 * nexuses to issue CDBs.
516 			 */
517 #if 0
518 			if (!registered_nexus) {
519 				pr_debug("Allowing implict CDB: 0x%02x"
520 					" for %s reservation on unregistered"
521 					" nexus\n", cdb[0],
522 					core_scsi3_pr_dump_type(pr_reg_type));
523 			}
524 #endif
525 			return 0;
526 		}
527 	} else if ((reg_only) || (all_reg)) {
528 		if (registered_nexus) {
529 			/*
530 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
531 			 * allow commands from registered nexuses.
532 			 */
533 #if 0
534 			pr_debug("Allowing implict CDB: 0x%02x for %s"
535 				" reservation\n", cdb[0],
536 				core_scsi3_pr_dump_type(pr_reg_type));
537 #endif
538 			return 0;
539 		}
540 	}
541 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
542 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
543 		(registered_nexus) ? "" : "un",
544 		se_sess->se_node_acl->initiatorname, cdb[0],
545 		core_scsi3_pr_dump_type(pr_reg_type));
546 
547 	return 1; /* Conflict by default */
548 }
549 
550 static u32 core_scsi3_pr_generation(struct se_device *dev)
551 {
552 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
553 	u32 prg;
554 	/*
555 	 * PRGeneration field shall contain the value of a 32-bit wrapping
556 	 * counter mainted by the device server.
557 	 *
558 	 * Note that this is done regardless of Active Persist across
559 	 * Target PowerLoss (APTPL)
560 	 *
561 	 * See spc4r17 section 6.3.12 READ_KEYS service action
562 	 */
563 	spin_lock(&dev->dev_reservation_lock);
564 	prg = su_dev->t10_pr.pr_generation++;
565 	spin_unlock(&dev->dev_reservation_lock);
566 
567 	return prg;
568 }
569 
570 static int core_scsi3_pr_reservation_check(
571 	struct se_cmd *cmd,
572 	u32 *pr_reg_type)
573 {
574 	struct se_device *dev = cmd->se_dev;
575 	struct se_session *sess = cmd->se_sess;
576 	int ret;
577 
578 	if (!sess)
579 		return 0;
580 	/*
581 	 * A legacy SPC-2 reservation is being held.
582 	 */
583 	if (dev->dev_flags & DF_SPC2_RESERVATIONS)
584 		return core_scsi2_reservation_check(cmd, pr_reg_type);
585 
586 	spin_lock(&dev->dev_reservation_lock);
587 	if (!dev->dev_pr_res_holder) {
588 		spin_unlock(&dev->dev_reservation_lock);
589 		return 0;
590 	}
591 	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
592 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
593 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) {
594 		spin_unlock(&dev->dev_reservation_lock);
595 		return -EINVAL;
596 	}
597 	if (!dev->dev_pr_res_holder->isid_present_at_reg) {
598 		spin_unlock(&dev->dev_reservation_lock);
599 		return 0;
600 	}
601 	ret = (dev->dev_pr_res_holder->pr_reg_bin_isid ==
602 	       sess->sess_bin_isid) ? 0 : -EINVAL;
603 	/*
604 	 * Use bit in *pr_reg_type to notify ISID mismatch in
605 	 * core_scsi3_pr_seq_non_holder().
606 	 */
607 	if (ret != 0)
608 		*pr_reg_type |= 0x80000000;
609 	spin_unlock(&dev->dev_reservation_lock);
610 
611 	return ret;
612 }
613 
614 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
615 	struct se_device *dev,
616 	struct se_node_acl *nacl,
617 	struct se_dev_entry *deve,
618 	unsigned char *isid,
619 	u64 sa_res_key,
620 	int all_tg_pt,
621 	int aptpl)
622 {
623 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
624 	struct t10_pr_registration *pr_reg;
625 
626 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
627 	if (!pr_reg) {
628 		pr_err("Unable to allocate struct t10_pr_registration\n");
629 		return NULL;
630 	}
631 
632 	pr_reg->pr_aptpl_buf = kzalloc(su_dev->t10_pr.pr_aptpl_buf_len,
633 					GFP_ATOMIC);
634 	if (!pr_reg->pr_aptpl_buf) {
635 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
636 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
637 		return NULL;
638 	}
639 
640 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
641 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
642 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
643 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
644 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
645 	atomic_set(&pr_reg->pr_res_holders, 0);
646 	pr_reg->pr_reg_nacl = nacl;
647 	pr_reg->pr_reg_deve = deve;
648 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
649 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
650 	pr_reg->pr_res_key = sa_res_key;
651 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
652 	pr_reg->pr_reg_aptpl = aptpl;
653 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
654 	/*
655 	 * If an ISID value for this SCSI Initiator Port exists,
656 	 * save it to the registration now.
657 	 */
658 	if (isid != NULL) {
659 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
660 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
661 		pr_reg->isid_present_at_reg = 1;
662 	}
663 
664 	return pr_reg;
665 }
666 
667 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
668 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
669 
670 /*
671  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
672  * modes.
673  */
674 static struct t10_pr_registration *__core_scsi3_alloc_registration(
675 	struct se_device *dev,
676 	struct se_node_acl *nacl,
677 	struct se_dev_entry *deve,
678 	unsigned char *isid,
679 	u64 sa_res_key,
680 	int all_tg_pt,
681 	int aptpl)
682 {
683 	struct se_dev_entry *deve_tmp;
684 	struct se_node_acl *nacl_tmp;
685 	struct se_port *port, *port_tmp;
686 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
687 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
688 	int ret;
689 	/*
690 	 * Create a registration for the I_T Nexus upon which the
691 	 * PROUT REGISTER was received.
692 	 */
693 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
694 			sa_res_key, all_tg_pt, aptpl);
695 	if (!pr_reg)
696 		return NULL;
697 	/*
698 	 * Return pointer to pr_reg for ALL_TG_PT=0
699 	 */
700 	if (!all_tg_pt)
701 		return pr_reg;
702 	/*
703 	 * Create list of matching SCSI Initiator Port registrations
704 	 * for ALL_TG_PT=1
705 	 */
706 	spin_lock(&dev->se_port_lock);
707 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
708 		atomic_inc(&port->sep_tg_pt_ref_cnt);
709 		smp_mb__after_atomic_inc();
710 		spin_unlock(&dev->se_port_lock);
711 
712 		spin_lock_bh(&port->sep_alua_lock);
713 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
714 					alua_port_list) {
715 			/*
716 			 * This pointer will be NULL for demo mode MappedLUNs
717 			 * that have not been make explict via a ConfigFS
718 			 * MappedLUN group for the SCSI Initiator Node ACL.
719 			 */
720 			if (!deve_tmp->se_lun_acl)
721 				continue;
722 
723 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
724 			/*
725 			 * Skip the matching struct se_node_acl that is allocated
726 			 * above..
727 			 */
728 			if (nacl == nacl_tmp)
729 				continue;
730 			/*
731 			 * Only perform PR registrations for target ports on
732 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
733 			 * arrived.
734 			 */
735 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
736 				continue;
737 			/*
738 			 * Look for a matching Initiator Node ACL in ASCII format
739 			 */
740 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
741 				continue;
742 
743 			atomic_inc(&deve_tmp->pr_ref_count);
744 			smp_mb__after_atomic_inc();
745 			spin_unlock_bh(&port->sep_alua_lock);
746 			/*
747 			 * Grab a configfs group dependency that is released
748 			 * for the exception path at label out: below, or upon
749 			 * completion of adding ALL_TG_PT=1 registrations in
750 			 * __core_scsi3_add_registration()
751 			 */
752 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
753 			if (ret < 0) {
754 				pr_err("core_scsi3_lunacl_depend"
755 						"_item() failed\n");
756 				atomic_dec(&port->sep_tg_pt_ref_cnt);
757 				smp_mb__after_atomic_dec();
758 				atomic_dec(&deve_tmp->pr_ref_count);
759 				smp_mb__after_atomic_dec();
760 				goto out;
761 			}
762 			/*
763 			 * Located a matching SCSI Initiator Port on a different
764 			 * port, allocate the pr_reg_atp and attach it to the
765 			 * pr_reg->pr_reg_atp_list that will be processed once
766 			 * the original *pr_reg is processed in
767 			 * __core_scsi3_add_registration()
768 			 */
769 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
770 						nacl_tmp, deve_tmp, NULL,
771 						sa_res_key, all_tg_pt, aptpl);
772 			if (!pr_reg_atp) {
773 				atomic_dec(&port->sep_tg_pt_ref_cnt);
774 				smp_mb__after_atomic_dec();
775 				atomic_dec(&deve_tmp->pr_ref_count);
776 				smp_mb__after_atomic_dec();
777 				core_scsi3_lunacl_undepend_item(deve_tmp);
778 				goto out;
779 			}
780 
781 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
782 				      &pr_reg->pr_reg_atp_list);
783 			spin_lock_bh(&port->sep_alua_lock);
784 		}
785 		spin_unlock_bh(&port->sep_alua_lock);
786 
787 		spin_lock(&dev->se_port_lock);
788 		atomic_dec(&port->sep_tg_pt_ref_cnt);
789 		smp_mb__after_atomic_dec();
790 	}
791 	spin_unlock(&dev->se_port_lock);
792 
793 	return pr_reg;
794 out:
795 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
796 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
797 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
798 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
799 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
800 	}
801 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
802 	return NULL;
803 }
804 
805 int core_scsi3_alloc_aptpl_registration(
806 	struct t10_reservation *pr_tmpl,
807 	u64 sa_res_key,
808 	unsigned char *i_port,
809 	unsigned char *isid,
810 	u32 mapped_lun,
811 	unsigned char *t_port,
812 	u16 tpgt,
813 	u32 target_lun,
814 	int res_holder,
815 	int all_tg_pt,
816 	u8 type)
817 {
818 	struct t10_pr_registration *pr_reg;
819 
820 	if (!i_port || !t_port || !sa_res_key) {
821 		pr_err("Illegal parameters for APTPL registration\n");
822 		return -EINVAL;
823 	}
824 
825 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
826 	if (!pr_reg) {
827 		pr_err("Unable to allocate struct t10_pr_registration\n");
828 		return -ENOMEM;
829 	}
830 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
831 
832 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
833 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
834 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
835 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
836 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
837 	atomic_set(&pr_reg->pr_res_holders, 0);
838 	pr_reg->pr_reg_nacl = NULL;
839 	pr_reg->pr_reg_deve = NULL;
840 	pr_reg->pr_res_mapped_lun = mapped_lun;
841 	pr_reg->pr_aptpl_target_lun = target_lun;
842 	pr_reg->pr_res_key = sa_res_key;
843 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
844 	pr_reg->pr_reg_aptpl = 1;
845 	pr_reg->pr_reg_tg_pt_lun = NULL;
846 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
847 	pr_reg->pr_res_type = type;
848 	/*
849 	 * If an ISID value had been saved in APTPL metadata for this
850 	 * SCSI Initiator Port, restore it now.
851 	 */
852 	if (isid != NULL) {
853 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
854 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
855 		pr_reg->isid_present_at_reg = 1;
856 	}
857 	/*
858 	 * Copy the i_port and t_port information from caller.
859 	 */
860 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
861 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
862 	pr_reg->pr_reg_tpgt = tpgt;
863 	/*
864 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
865 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
866 	 * the Initiator Node LUN ACL from the fabric module is created for
867 	 * this registration.
868 	 */
869 	pr_reg->pr_res_holder = res_holder;
870 
871 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
872 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
873 			" metadata\n", (res_holder) ? "+reservation" : "");
874 	return 0;
875 }
876 
877 static void core_scsi3_aptpl_reserve(
878 	struct se_device *dev,
879 	struct se_portal_group *tpg,
880 	struct se_node_acl *node_acl,
881 	struct t10_pr_registration *pr_reg)
882 {
883 	char i_buf[PR_REG_ISID_ID_LEN];
884 	int prf_isid;
885 
886 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
887 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
888 				PR_REG_ISID_ID_LEN);
889 
890 	spin_lock(&dev->dev_reservation_lock);
891 	dev->dev_pr_res_holder = pr_reg;
892 	spin_unlock(&dev->dev_reservation_lock);
893 
894 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
895 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
896 		tpg->se_tpg_tfo->get_fabric_name(),
897 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
898 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
899 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
900 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
901 		(prf_isid) ? &i_buf[0] : "");
902 }
903 
904 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
905 				struct t10_pr_registration *, int, int);
906 
907 static int __core_scsi3_check_aptpl_registration(
908 	struct se_device *dev,
909 	struct se_portal_group *tpg,
910 	struct se_lun *lun,
911 	u32 target_lun,
912 	struct se_node_acl *nacl,
913 	struct se_dev_entry *deve)
914 {
915 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
916 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
917 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
918 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
919 	u16 tpgt;
920 
921 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
922 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
923 	/*
924 	 * Copy Initiator Port information from struct se_node_acl
925 	 */
926 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
927 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
928 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
929 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
930 	/*
931 	 * Look for the matching registrations+reservation from those
932 	 * created from APTPL metadata.  Note that multiple registrations
933 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
934 	 * TransportIDs.
935 	 */
936 	spin_lock(&pr_tmpl->aptpl_reg_lock);
937 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
938 				pr_reg_aptpl_list) {
939 		if (!strcmp(pr_reg->pr_iport, i_port) &&
940 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
941 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
942 		     (pr_reg->pr_reg_tpgt == tpgt) &&
943 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
944 
945 			pr_reg->pr_reg_nacl = nacl;
946 			pr_reg->pr_reg_deve = deve;
947 			pr_reg->pr_reg_tg_pt_lun = lun;
948 
949 			list_del(&pr_reg->pr_reg_aptpl_list);
950 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
951 			/*
952 			 * At this point all of the pointers in *pr_reg will
953 			 * be setup, so go ahead and add the registration.
954 			 */
955 
956 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
957 			/*
958 			 * If this registration is the reservation holder,
959 			 * make that happen now..
960 			 */
961 			if (pr_reg->pr_res_holder)
962 				core_scsi3_aptpl_reserve(dev, tpg,
963 						nacl, pr_reg);
964 			/*
965 			 * Reenable pr_aptpl_active to accept new metadata
966 			 * updates once the SCSI device is active again..
967 			 */
968 			spin_lock(&pr_tmpl->aptpl_reg_lock);
969 			pr_tmpl->pr_aptpl_active = 1;
970 		}
971 	}
972 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
973 
974 	return 0;
975 }
976 
977 int core_scsi3_check_aptpl_registration(
978 	struct se_device *dev,
979 	struct se_portal_group *tpg,
980 	struct se_lun *lun,
981 	struct se_lun_acl *lun_acl)
982 {
983 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
984 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
985 	struct se_dev_entry *deve = &nacl->device_list[lun_acl->mapped_lun];
986 
987 	if (su_dev->t10_pr.res_type != SPC3_PERSISTENT_RESERVATIONS)
988 		return 0;
989 
990 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
991 				lun->unpacked_lun, nacl, deve);
992 }
993 
994 static void __core_scsi3_dump_registration(
995 	struct target_core_fabric_ops *tfo,
996 	struct se_device *dev,
997 	struct se_node_acl *nacl,
998 	struct t10_pr_registration *pr_reg,
999 	int register_type)
1000 {
1001 	struct se_portal_group *se_tpg = nacl->se_tpg;
1002 	char i_buf[PR_REG_ISID_ID_LEN];
1003 	int prf_isid;
1004 
1005 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1006 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1007 				PR_REG_ISID_ID_LEN);
1008 
1009 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1010 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
1011 		"_AND_MOVE" : (register_type == 1) ?
1012 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1013 		(prf_isid) ? i_buf : "");
1014 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1015 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1016 		tfo->tpg_get_tag(se_tpg));
1017 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1018 		" Port(s)\n",  tfo->get_fabric_name(),
1019 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1020 		dev->transport->name);
1021 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1022 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1023 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1024 		pr_reg->pr_reg_aptpl);
1025 }
1026 
1027 /*
1028  * this function can be called with struct se_device->dev_reservation_lock
1029  * when register_move = 1
1030  */
1031 static void __core_scsi3_add_registration(
1032 	struct se_device *dev,
1033 	struct se_node_acl *nacl,
1034 	struct t10_pr_registration *pr_reg,
1035 	int register_type,
1036 	int register_move)
1037 {
1038 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1039 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1040 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1041 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1042 
1043 	/*
1044 	 * Increment PRgeneration counter for struct se_device upon a successful
1045 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1046 	 *
1047 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1048 	 * action, the struct se_device->dev_reservation_lock will already be held,
1049 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1050 	 * for the REGISTER.
1051 	 */
1052 	pr_reg->pr_res_generation = (register_move) ?
1053 			su_dev->t10_pr.pr_generation++ :
1054 			core_scsi3_pr_generation(dev);
1055 
1056 	spin_lock(&pr_tmpl->registration_lock);
1057 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1058 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1059 
1060 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1061 	spin_unlock(&pr_tmpl->registration_lock);
1062 	/*
1063 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1064 	 */
1065 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1066 		return;
1067 	/*
1068 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1069 	 * allocated in __core_scsi3_alloc_registration()
1070 	 */
1071 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1072 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1073 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1074 
1075 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1076 
1077 		spin_lock(&pr_tmpl->registration_lock);
1078 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1079 			      &pr_tmpl->registration_list);
1080 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1081 
1082 		__core_scsi3_dump_registration(tfo, dev,
1083 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1084 				register_type);
1085 		spin_unlock(&pr_tmpl->registration_lock);
1086 		/*
1087 		 * Drop configfs group dependency reference from
1088 		 * __core_scsi3_alloc_registration()
1089 		 */
1090 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1091 	}
1092 }
1093 
1094 static int core_scsi3_alloc_registration(
1095 	struct se_device *dev,
1096 	struct se_node_acl *nacl,
1097 	struct se_dev_entry *deve,
1098 	unsigned char *isid,
1099 	u64 sa_res_key,
1100 	int all_tg_pt,
1101 	int aptpl,
1102 	int register_type,
1103 	int register_move)
1104 {
1105 	struct t10_pr_registration *pr_reg;
1106 
1107 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1108 			sa_res_key, all_tg_pt, aptpl);
1109 	if (!pr_reg)
1110 		return -EPERM;
1111 
1112 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1113 			register_type, register_move);
1114 	return 0;
1115 }
1116 
1117 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1118 	struct se_device *dev,
1119 	struct se_node_acl *nacl,
1120 	unsigned char *isid)
1121 {
1122 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1123 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1124 	struct se_portal_group *tpg;
1125 
1126 	spin_lock(&pr_tmpl->registration_lock);
1127 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1128 			&pr_tmpl->registration_list, pr_reg_list) {
1129 		/*
1130 		 * First look for a matching struct se_node_acl
1131 		 */
1132 		if (pr_reg->pr_reg_nacl != nacl)
1133 			continue;
1134 
1135 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1136 		/*
1137 		 * If this registration does NOT contain a fabric provided
1138 		 * ISID, then we have found a match.
1139 		 */
1140 		if (!pr_reg->isid_present_at_reg) {
1141 			/*
1142 			 * Determine if this SCSI device server requires that
1143 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1144 			 * for fabric modules (iSCSI) requiring them.
1145 			 */
1146 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1147 				if (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids)
1148 					continue;
1149 			}
1150 			atomic_inc(&pr_reg->pr_res_holders);
1151 			smp_mb__after_atomic_inc();
1152 			spin_unlock(&pr_tmpl->registration_lock);
1153 			return pr_reg;
1154 		}
1155 		/*
1156 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1157 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1158 		 * matching ISID to be provided by the local SCSI Initiator Port.
1159 		 */
1160 		if (!isid)
1161 			continue;
1162 		if (strcmp(isid, pr_reg->pr_reg_isid))
1163 			continue;
1164 
1165 		atomic_inc(&pr_reg->pr_res_holders);
1166 		smp_mb__after_atomic_inc();
1167 		spin_unlock(&pr_tmpl->registration_lock);
1168 		return pr_reg;
1169 	}
1170 	spin_unlock(&pr_tmpl->registration_lock);
1171 
1172 	return NULL;
1173 }
1174 
1175 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1176 	struct se_device *dev,
1177 	struct se_node_acl *nacl,
1178 	struct se_session *sess)
1179 {
1180 	struct se_portal_group *tpg = nacl->se_tpg;
1181 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1182 
1183 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1184 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1185 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1186 					PR_REG_ISID_LEN);
1187 		isid_ptr = &buf[0];
1188 	}
1189 
1190 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1191 }
1192 
1193 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1194 {
1195 	atomic_dec(&pr_reg->pr_res_holders);
1196 	smp_mb__after_atomic_dec();
1197 }
1198 
1199 static int core_scsi3_check_implict_release(
1200 	struct se_device *dev,
1201 	struct t10_pr_registration *pr_reg)
1202 {
1203 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1204 	struct t10_pr_registration *pr_res_holder;
1205 	int ret = 0;
1206 
1207 	spin_lock(&dev->dev_reservation_lock);
1208 	pr_res_holder = dev->dev_pr_res_holder;
1209 	if (!pr_res_holder) {
1210 		spin_unlock(&dev->dev_reservation_lock);
1211 		return ret;
1212 	}
1213 	if (pr_res_holder == pr_reg) {
1214 		/*
1215 		 * Perform an implict RELEASE if the registration that
1216 		 * is being released is holding the reservation.
1217 		 *
1218 		 * From spc4r17, section 5.7.11.1:
1219 		 *
1220 		 * e) If the I_T nexus is the persistent reservation holder
1221 		 *    and the persistent reservation is not an all registrants
1222 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1223 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1224 		 *    service action with the SERVICE ACTION RESERVATION KEY
1225 		 *    field set to zero (see 5.7.11.3).
1226 		 */
1227 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1228 		ret = 1;
1229 		/*
1230 		 * For 'All Registrants' reservation types, all existing
1231 		 * registrations are still processed as reservation holders
1232 		 * in core_scsi3_pr_seq_non_holder() after the initial
1233 		 * reservation holder is implictly released here.
1234 		 */
1235 	} else if (pr_reg->pr_reg_all_tg_pt &&
1236 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1237 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1238 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1239 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1240 			" UNREGISTER while existing reservation with matching"
1241 			" key 0x%016Lx is present from another SCSI Initiator"
1242 			" Port\n", pr_reg->pr_res_key);
1243 		ret = -EPERM;
1244 	}
1245 	spin_unlock(&dev->dev_reservation_lock);
1246 
1247 	return ret;
1248 }
1249 
1250 /*
1251  * Called with struct t10_reservation->registration_lock held.
1252  */
1253 static void __core_scsi3_free_registration(
1254 	struct se_device *dev,
1255 	struct t10_pr_registration *pr_reg,
1256 	struct list_head *preempt_and_abort_list,
1257 	int dec_holders)
1258 {
1259 	struct target_core_fabric_ops *tfo =
1260 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1261 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1262 	char i_buf[PR_REG_ISID_ID_LEN];
1263 	int prf_isid;
1264 
1265 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1266 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1267 				PR_REG_ISID_ID_LEN);
1268 
1269 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1270 	pr_reg->pr_reg_deve->pr_res_key = 0;
1271 	list_del(&pr_reg->pr_reg_list);
1272 	/*
1273 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1274 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1275 	 */
1276 	if (dec_holders)
1277 		core_scsi3_put_pr_reg(pr_reg);
1278 	/*
1279 	 * Wait until all reference from any other I_T nexuses for this
1280 	 * *pr_reg have been released.  Because list_del() is called above,
1281 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1282 	 * count back to zero, and we release *pr_reg.
1283 	 */
1284 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1285 		spin_unlock(&pr_tmpl->registration_lock);
1286 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1287 				tfo->get_fabric_name());
1288 		cpu_relax();
1289 		spin_lock(&pr_tmpl->registration_lock);
1290 	}
1291 
1292 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1293 		" Node: %s%s\n", tfo->get_fabric_name(),
1294 		pr_reg->pr_reg_nacl->initiatorname,
1295 		(prf_isid) ? &i_buf[0] : "");
1296 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1297 		" Port(s)\n", tfo->get_fabric_name(),
1298 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1299 		dev->transport->name);
1300 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1301 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1302 		pr_reg->pr_res_generation);
1303 
1304 	if (!preempt_and_abort_list) {
1305 		pr_reg->pr_reg_deve = NULL;
1306 		pr_reg->pr_reg_nacl = NULL;
1307 		kfree(pr_reg->pr_aptpl_buf);
1308 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1309 		return;
1310 	}
1311 	/*
1312 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1313 	 * are released once the ABORT_TASK_SET has completed..
1314 	 */
1315 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1316 }
1317 
1318 void core_scsi3_free_pr_reg_from_nacl(
1319 	struct se_device *dev,
1320 	struct se_node_acl *nacl)
1321 {
1322 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1323 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1324 	/*
1325 	 * If the passed se_node_acl matches the reservation holder,
1326 	 * release the reservation.
1327 	 */
1328 	spin_lock(&dev->dev_reservation_lock);
1329 	pr_res_holder = dev->dev_pr_res_holder;
1330 	if ((pr_res_holder != NULL) &&
1331 	    (pr_res_holder->pr_reg_nacl == nacl))
1332 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1333 	spin_unlock(&dev->dev_reservation_lock);
1334 	/*
1335 	 * Release any registration associated with the struct se_node_acl.
1336 	 */
1337 	spin_lock(&pr_tmpl->registration_lock);
1338 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1339 			&pr_tmpl->registration_list, pr_reg_list) {
1340 
1341 		if (pr_reg->pr_reg_nacl != nacl)
1342 			continue;
1343 
1344 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1345 	}
1346 	spin_unlock(&pr_tmpl->registration_lock);
1347 }
1348 
1349 void core_scsi3_free_all_registrations(
1350 	struct se_device *dev)
1351 {
1352 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1353 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1354 
1355 	spin_lock(&dev->dev_reservation_lock);
1356 	pr_res_holder = dev->dev_pr_res_holder;
1357 	if (pr_res_holder != NULL) {
1358 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1359 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1360 				pr_res_holder, 0);
1361 	}
1362 	spin_unlock(&dev->dev_reservation_lock);
1363 
1364 	spin_lock(&pr_tmpl->registration_lock);
1365 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1366 			&pr_tmpl->registration_list, pr_reg_list) {
1367 
1368 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1369 	}
1370 	spin_unlock(&pr_tmpl->registration_lock);
1371 
1372 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1373 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1374 				pr_reg_aptpl_list) {
1375 		list_del(&pr_reg->pr_reg_aptpl_list);
1376 		kfree(pr_reg->pr_aptpl_buf);
1377 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1378 	}
1379 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1380 }
1381 
1382 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1383 {
1384 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1385 			&tpg->tpg_group.cg_item);
1386 }
1387 
1388 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1389 {
1390 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1391 			&tpg->tpg_group.cg_item);
1392 
1393 	atomic_dec(&tpg->tpg_pr_ref_count);
1394 	smp_mb__after_atomic_dec();
1395 }
1396 
1397 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1398 {
1399 	struct se_portal_group *tpg = nacl->se_tpg;
1400 
1401 	if (nacl->dynamic_node_acl)
1402 		return 0;
1403 
1404 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1405 			&nacl->acl_group.cg_item);
1406 }
1407 
1408 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1409 {
1410 	struct se_portal_group *tpg = nacl->se_tpg;
1411 
1412 	if (nacl->dynamic_node_acl) {
1413 		atomic_dec(&nacl->acl_pr_ref_count);
1414 		smp_mb__after_atomic_dec();
1415 		return;
1416 	}
1417 
1418 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1419 			&nacl->acl_group.cg_item);
1420 
1421 	atomic_dec(&nacl->acl_pr_ref_count);
1422 	smp_mb__after_atomic_dec();
1423 }
1424 
1425 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1426 {
1427 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1428 	struct se_node_acl *nacl;
1429 	struct se_portal_group *tpg;
1430 	/*
1431 	 * For nacl->dynamic_node_acl=1
1432 	 */
1433 	if (!lun_acl)
1434 		return 0;
1435 
1436 	nacl = lun_acl->se_lun_nacl;
1437 	tpg = nacl->se_tpg;
1438 
1439 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1440 			&lun_acl->se_lun_group.cg_item);
1441 }
1442 
1443 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1444 {
1445 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1446 	struct se_node_acl *nacl;
1447 	struct se_portal_group *tpg;
1448 	/*
1449 	 * For nacl->dynamic_node_acl=1
1450 	 */
1451 	if (!lun_acl) {
1452 		atomic_dec(&se_deve->pr_ref_count);
1453 		smp_mb__after_atomic_dec();
1454 		return;
1455 	}
1456 	nacl = lun_acl->se_lun_nacl;
1457 	tpg = nacl->se_tpg;
1458 
1459 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1460 			&lun_acl->se_lun_group.cg_item);
1461 
1462 	atomic_dec(&se_deve->pr_ref_count);
1463 	smp_mb__after_atomic_dec();
1464 }
1465 
1466 static int core_scsi3_decode_spec_i_port(
1467 	struct se_cmd *cmd,
1468 	struct se_portal_group *tpg,
1469 	unsigned char *l_isid,
1470 	u64 sa_res_key,
1471 	int all_tg_pt,
1472 	int aptpl)
1473 {
1474 	struct se_device *dev = cmd->se_dev;
1475 	struct se_port *tmp_port;
1476 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1477 	struct se_session *se_sess = cmd->se_sess;
1478 	struct se_node_acl *dest_node_acl = NULL;
1479 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1480 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1481 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1482 	struct list_head tid_dest_list;
1483 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1484 	struct target_core_fabric_ops *tmp_tf_ops;
1485 	unsigned char *buf;
1486 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1487 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1488 	u32 tpdl, tid_len = 0;
1489 	int ret, dest_local_nexus, prf_isid;
1490 	u32 dest_rtpi = 0;
1491 
1492 	memset(dest_iport, 0, 64);
1493 	INIT_LIST_HEAD(&tid_dest_list);
1494 
1495 	local_se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1496 	/*
1497 	 * Allocate a struct pr_transport_id_holder and setup the
1498 	 * local_node_acl and local_se_deve pointers and add to
1499 	 * struct list_head tid_dest_list for add registration
1500 	 * processing in the loop of tid_dest_list below.
1501 	 */
1502 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1503 	if (!tidh_new) {
1504 		pr_err("Unable to allocate tidh_new\n");
1505 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1506 	}
1507 	INIT_LIST_HEAD(&tidh_new->dest_list);
1508 	tidh_new->dest_tpg = tpg;
1509 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1510 	tidh_new->dest_se_deve = local_se_deve;
1511 
1512 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1513 				se_sess->se_node_acl, local_se_deve, l_isid,
1514 				sa_res_key, all_tg_pt, aptpl);
1515 	if (!local_pr_reg) {
1516 		kfree(tidh_new);
1517 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1518 	}
1519 	tidh_new->dest_pr_reg = local_pr_reg;
1520 	/*
1521 	 * The local I_T nexus does not hold any configfs dependances,
1522 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1523 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1524 	 */
1525 	tidh_new->dest_local_nexus = 1;
1526 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1527 
1528 	buf = transport_kmap_first_data_page(cmd);
1529 	/*
1530 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1531 	 * first extract TransportID Parameter Data Length, and make sure
1532 	 * the value matches up to the SCSI expected data transfer length.
1533 	 */
1534 	tpdl = (buf[24] & 0xff) << 24;
1535 	tpdl |= (buf[25] & 0xff) << 16;
1536 	tpdl |= (buf[26] & 0xff) << 8;
1537 	tpdl |= buf[27] & 0xff;
1538 
1539 	if ((tpdl + 28) != cmd->data_length) {
1540 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1541 			" does not equal CDB data_length: %u\n", tpdl,
1542 			cmd->data_length);
1543 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1544 		goto out;
1545 	}
1546 	/*
1547 	 * Start processing the received transport IDs using the
1548 	 * receiving I_T Nexus portal's fabric dependent methods to
1549 	 * obtain the SCSI Initiator Port/Device Identifiers.
1550 	 */
1551 	ptr = &buf[28];
1552 
1553 	while (tpdl > 0) {
1554 		proto_ident = (ptr[0] & 0x0f);
1555 		dest_tpg = NULL;
1556 
1557 		spin_lock(&dev->se_port_lock);
1558 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1559 			tmp_tpg = tmp_port->sep_tpg;
1560 			if (!tmp_tpg)
1561 				continue;
1562 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1563 			if (!tmp_tf_ops)
1564 				continue;
1565 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1566 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1567 				continue;
1568 			/*
1569 			 * Look for the matching proto_ident provided by
1570 			 * the received TransportID
1571 			 */
1572 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1573 			if (tmp_proto_ident != proto_ident)
1574 				continue;
1575 			dest_rtpi = tmp_port->sep_rtpi;
1576 
1577 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1578 					tmp_tpg, (const char *)ptr, &tid_len,
1579 					&iport_ptr);
1580 			if (!i_str)
1581 				continue;
1582 
1583 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1584 			smp_mb__after_atomic_inc();
1585 			spin_unlock(&dev->se_port_lock);
1586 
1587 			ret = core_scsi3_tpg_depend_item(tmp_tpg);
1588 			if (ret != 0) {
1589 				pr_err(" core_scsi3_tpg_depend_item()"
1590 					" for tmp_tpg\n");
1591 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1592 				smp_mb__after_atomic_dec();
1593 				ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1594 				goto out;
1595 			}
1596 			/*
1597 			 * Locate the desination initiator ACL to be registered
1598 			 * from the decoded fabric module specific TransportID
1599 			 * at *i_str.
1600 			 */
1601 			spin_lock_bh(&tmp_tpg->acl_node_lock);
1602 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1603 						tmp_tpg, i_str);
1604 			if (dest_node_acl) {
1605 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1606 				smp_mb__after_atomic_inc();
1607 			}
1608 			spin_unlock_bh(&tmp_tpg->acl_node_lock);
1609 
1610 			if (!dest_node_acl) {
1611 				core_scsi3_tpg_undepend_item(tmp_tpg);
1612 				spin_lock(&dev->se_port_lock);
1613 				continue;
1614 			}
1615 
1616 			ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
1617 			if (ret != 0) {
1618 				pr_err("configfs_depend_item() failed"
1619 					" for dest_node_acl->acl_group\n");
1620 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1621 				smp_mb__after_atomic_dec();
1622 				core_scsi3_tpg_undepend_item(tmp_tpg);
1623 				ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1624 				goto out;
1625 			}
1626 
1627 			dest_tpg = tmp_tpg;
1628 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1629 				" %s Port RTPI: %hu\n",
1630 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1631 				dest_node_acl->initiatorname, dest_rtpi);
1632 
1633 			spin_lock(&dev->se_port_lock);
1634 			break;
1635 		}
1636 		spin_unlock(&dev->se_port_lock);
1637 
1638 		if (!dest_tpg) {
1639 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1640 					" dest_tpg\n");
1641 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1642 			goto out;
1643 		}
1644 #if 0
1645 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1646 			" tid_len: %d for %s + %s\n",
1647 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1648 			tpdl, tid_len, i_str, iport_ptr);
1649 #endif
1650 		if (tid_len > tpdl) {
1651 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1652 				" %u for Transport ID: %s\n", tid_len, ptr);
1653 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1654 			core_scsi3_tpg_undepend_item(dest_tpg);
1655 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1656 			goto out;
1657 		}
1658 		/*
1659 		 * Locate the desintation struct se_dev_entry pointer for matching
1660 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1661 		 * Target Port.
1662 		 */
1663 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1664 					dest_rtpi);
1665 		if (!dest_se_deve) {
1666 			pr_err("Unable to locate %s dest_se_deve"
1667 				" from destination RTPI: %hu\n",
1668 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1669 				dest_rtpi);
1670 
1671 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1672 			core_scsi3_tpg_undepend_item(dest_tpg);
1673 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1674 			goto out;
1675 		}
1676 
1677 		ret = core_scsi3_lunacl_depend_item(dest_se_deve);
1678 		if (ret < 0) {
1679 			pr_err("core_scsi3_lunacl_depend_item()"
1680 					" failed\n");
1681 			atomic_dec(&dest_se_deve->pr_ref_count);
1682 			smp_mb__after_atomic_dec();
1683 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1684 			core_scsi3_tpg_undepend_item(dest_tpg);
1685 			ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1686 			goto out;
1687 		}
1688 #if 0
1689 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1690 			" dest_se_deve mapped_lun: %u\n",
1691 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1692 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1693 #endif
1694 		/*
1695 		 * Skip any TransportIDs that already have a registration for
1696 		 * this target port.
1697 		 */
1698 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1699 					iport_ptr);
1700 		if (pr_reg_e) {
1701 			core_scsi3_put_pr_reg(pr_reg_e);
1702 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1703 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1704 			core_scsi3_tpg_undepend_item(dest_tpg);
1705 			ptr += tid_len;
1706 			tpdl -= tid_len;
1707 			tid_len = 0;
1708 			continue;
1709 		}
1710 		/*
1711 		 * Allocate a struct pr_transport_id_holder and setup
1712 		 * the dest_node_acl and dest_se_deve pointers for the
1713 		 * loop below.
1714 		 */
1715 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1716 				GFP_KERNEL);
1717 		if (!tidh_new) {
1718 			pr_err("Unable to allocate tidh_new\n");
1719 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1720 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1721 			core_scsi3_tpg_undepend_item(dest_tpg);
1722 			ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1723 			goto out;
1724 		}
1725 		INIT_LIST_HEAD(&tidh_new->dest_list);
1726 		tidh_new->dest_tpg = dest_tpg;
1727 		tidh_new->dest_node_acl = dest_node_acl;
1728 		tidh_new->dest_se_deve = dest_se_deve;
1729 
1730 		/*
1731 		 * Allocate, but do NOT add the registration for the
1732 		 * TransportID referenced SCSI Initiator port.  This
1733 		 * done because of the following from spc4r17 in section
1734 		 * 6.14.3 wrt SPEC_I_PT:
1735 		 *
1736 		 * "If a registration fails for any initiator port (e.g., if th
1737 		 * logical unit does not have enough resources available to
1738 		 * hold the registration information), no registrations shall be
1739 		 * made, and the command shall be terminated with
1740 		 * CHECK CONDITION status."
1741 		 *
1742 		 * That means we call __core_scsi3_alloc_registration() here,
1743 		 * and then call __core_scsi3_add_registration() in the
1744 		 * 2nd loop which will never fail.
1745 		 */
1746 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1747 				dest_node_acl, dest_se_deve, iport_ptr,
1748 				sa_res_key, all_tg_pt, aptpl);
1749 		if (!dest_pr_reg) {
1750 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1751 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1752 			core_scsi3_tpg_undepend_item(dest_tpg);
1753 			kfree(tidh_new);
1754 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1755 			goto out;
1756 		}
1757 		tidh_new->dest_pr_reg = dest_pr_reg;
1758 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1759 
1760 		ptr += tid_len;
1761 		tpdl -= tid_len;
1762 		tid_len = 0;
1763 
1764 	}
1765 
1766 	transport_kunmap_first_data_page(cmd);
1767 
1768 	/*
1769 	 * Go ahead and create a registrations from tid_dest_list for the
1770 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1771 	 * and dest_se_deve.
1772 	 *
1773 	 * The SA Reservation Key from the PROUT is set for the
1774 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1775 	 * means that the TransportID Initiator port will be
1776 	 * registered on all of the target ports in the SCSI target device
1777 	 * ALL_TG_PT=0 means the registration will only be for the
1778 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1779 	 * was received.
1780 	 */
1781 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1782 		dest_tpg = tidh->dest_tpg;
1783 		dest_node_acl = tidh->dest_node_acl;
1784 		dest_se_deve = tidh->dest_se_deve;
1785 		dest_pr_reg = tidh->dest_pr_reg;
1786 		dest_local_nexus = tidh->dest_local_nexus;
1787 
1788 		list_del(&tidh->dest_list);
1789 		kfree(tidh);
1790 
1791 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1792 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1793 						PR_REG_ISID_ID_LEN);
1794 
1795 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1796 					dest_pr_reg, 0, 0);
1797 
1798 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1799 			" registered Transport ID for Node: %s%s Mapped LUN:"
1800 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1801 			dest_node_acl->initiatorname, (prf_isid) ?
1802 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1803 
1804 		if (dest_local_nexus)
1805 			continue;
1806 
1807 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1808 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1809 		core_scsi3_tpg_undepend_item(dest_tpg);
1810 	}
1811 
1812 	return 0;
1813 out:
1814 	transport_kunmap_first_data_page(cmd);
1815 	/*
1816 	 * For the failure case, release everything from tid_dest_list
1817 	 * including *dest_pr_reg and the configfs dependances..
1818 	 */
1819 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1820 		dest_tpg = tidh->dest_tpg;
1821 		dest_node_acl = tidh->dest_node_acl;
1822 		dest_se_deve = tidh->dest_se_deve;
1823 		dest_pr_reg = tidh->dest_pr_reg;
1824 		dest_local_nexus = tidh->dest_local_nexus;
1825 
1826 		list_del(&tidh->dest_list);
1827 		kfree(tidh);
1828 		/*
1829 		 * Release any extra ALL_TG_PT=1 registrations for
1830 		 * the SPEC_I_PT=1 case.
1831 		 */
1832 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1833 				&dest_pr_reg->pr_reg_atp_list,
1834 				pr_reg_atp_mem_list) {
1835 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1836 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1837 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1838 		}
1839 
1840 		kfree(dest_pr_reg->pr_aptpl_buf);
1841 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1842 
1843 		if (dest_local_nexus)
1844 			continue;
1845 
1846 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1847 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1848 		core_scsi3_tpg_undepend_item(dest_tpg);
1849 	}
1850 	return ret;
1851 }
1852 
1853 /*
1854  * Called with struct se_device->dev_reservation_lock held
1855  */
1856 static int __core_scsi3_update_aptpl_buf(
1857 	struct se_device *dev,
1858 	unsigned char *buf,
1859 	u32 pr_aptpl_buf_len,
1860 	int clear_aptpl_metadata)
1861 {
1862 	struct se_lun *lun;
1863 	struct se_portal_group *tpg;
1864 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1865 	struct t10_pr_registration *pr_reg;
1866 	unsigned char tmp[512], isid_buf[32];
1867 	ssize_t len = 0;
1868 	int reg_count = 0;
1869 
1870 	memset(buf, 0, pr_aptpl_buf_len);
1871 	/*
1872 	 * Called to clear metadata once APTPL has been deactivated.
1873 	 */
1874 	if (clear_aptpl_metadata) {
1875 		snprintf(buf, pr_aptpl_buf_len,
1876 				"No Registrations or Reservations\n");
1877 		return 0;
1878 	}
1879 	/*
1880 	 * Walk the registration list..
1881 	 */
1882 	spin_lock(&su_dev->t10_pr.registration_lock);
1883 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
1884 			pr_reg_list) {
1885 
1886 		tmp[0] = '\0';
1887 		isid_buf[0] = '\0';
1888 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1889 		lun = pr_reg->pr_reg_tg_pt_lun;
1890 		/*
1891 		 * Write out any ISID value to APTPL metadata that was included
1892 		 * in the original registration.
1893 		 */
1894 		if (pr_reg->isid_present_at_reg)
1895 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1896 					pr_reg->pr_reg_isid);
1897 		/*
1898 		 * Include special metadata if the pr_reg matches the
1899 		 * reservation holder.
1900 		 */
1901 		if (dev->dev_pr_res_holder == pr_reg) {
1902 			snprintf(tmp, 512, "PR_REG_START: %d"
1903 				"\ninitiator_fabric=%s\n"
1904 				"initiator_node=%s\n%s"
1905 				"sa_res_key=%llu\n"
1906 				"res_holder=1\nres_type=%02x\n"
1907 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1908 				"mapped_lun=%u\n", reg_count,
1909 				tpg->se_tpg_tfo->get_fabric_name(),
1910 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1911 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1912 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1913 				pr_reg->pr_res_mapped_lun);
1914 		} else {
1915 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1916 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1917 				"sa_res_key=%llu\nres_holder=0\n"
1918 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1919 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1920 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1921 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1922 				pr_reg->pr_res_mapped_lun);
1923 		}
1924 
1925 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1926 			pr_err("Unable to update renaming"
1927 				" APTPL metadata\n");
1928 			spin_unlock(&su_dev->t10_pr.registration_lock);
1929 			return -EMSGSIZE;
1930 		}
1931 		len += sprintf(buf+len, "%s", tmp);
1932 
1933 		/*
1934 		 * Include information about the associated SCSI target port.
1935 		 */
1936 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1937 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1938 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1939 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1940 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1941 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1942 
1943 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1944 			pr_err("Unable to update renaming"
1945 				" APTPL metadata\n");
1946 			spin_unlock(&su_dev->t10_pr.registration_lock);
1947 			return -EMSGSIZE;
1948 		}
1949 		len += sprintf(buf+len, "%s", tmp);
1950 		reg_count++;
1951 	}
1952 	spin_unlock(&su_dev->t10_pr.registration_lock);
1953 
1954 	if (!reg_count)
1955 		len += sprintf(buf+len, "No Registrations or Reservations");
1956 
1957 	return 0;
1958 }
1959 
1960 static int core_scsi3_update_aptpl_buf(
1961 	struct se_device *dev,
1962 	unsigned char *buf,
1963 	u32 pr_aptpl_buf_len,
1964 	int clear_aptpl_metadata)
1965 {
1966 	int ret;
1967 
1968 	spin_lock(&dev->dev_reservation_lock);
1969 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
1970 				clear_aptpl_metadata);
1971 	spin_unlock(&dev->dev_reservation_lock);
1972 
1973 	return ret;
1974 }
1975 
1976 /*
1977  * Called with struct se_device->aptpl_file_mutex held
1978  */
1979 static int __core_scsi3_write_aptpl_to_file(
1980 	struct se_device *dev,
1981 	unsigned char *buf,
1982 	u32 pr_aptpl_buf_len)
1983 {
1984 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
1985 	struct file *file;
1986 	struct iovec iov[1];
1987 	mm_segment_t old_fs;
1988 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1989 	char path[512];
1990 	int ret;
1991 
1992 	memset(iov, 0, sizeof(struct iovec));
1993 	memset(path, 0, 512);
1994 
1995 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1996 		pr_err("WWN value for struct se_device does not fit"
1997 			" into path buffer\n");
1998 		return -EMSGSIZE;
1999 	}
2000 
2001 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
2002 	file = filp_open(path, flags, 0600);
2003 	if (IS_ERR(file) || !file || !file->f_dentry) {
2004 		pr_err("filp_open(%s) for APTPL metadata"
2005 			" failed\n", path);
2006 		return (PTR_ERR(file) < 0 ? PTR_ERR(file) : -ENOENT);
2007 	}
2008 
2009 	iov[0].iov_base = &buf[0];
2010 	if (!pr_aptpl_buf_len)
2011 		iov[0].iov_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
2012 	else
2013 		iov[0].iov_len = pr_aptpl_buf_len;
2014 
2015 	old_fs = get_fs();
2016 	set_fs(get_ds());
2017 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
2018 	set_fs(old_fs);
2019 
2020 	if (ret < 0) {
2021 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2022 		filp_close(file, NULL);
2023 		return -EIO;
2024 	}
2025 	filp_close(file, NULL);
2026 
2027 	return 0;
2028 }
2029 
2030 static int core_scsi3_update_and_write_aptpl(
2031 	struct se_device *dev,
2032 	unsigned char *in_buf,
2033 	u32 in_pr_aptpl_buf_len)
2034 {
2035 	unsigned char null_buf[64], *buf;
2036 	u32 pr_aptpl_buf_len;
2037 	int ret, clear_aptpl_metadata = 0;
2038 	/*
2039 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2040 	 */
2041 	if (!in_buf) {
2042 		memset(null_buf, 0, 64);
2043 		buf = &null_buf[0];
2044 		/*
2045 		 * This will clear the APTPL metadata to:
2046 		 * "No Registrations or Reservations" status
2047 		 */
2048 		pr_aptpl_buf_len = 64;
2049 		clear_aptpl_metadata = 1;
2050 	} else {
2051 		buf = in_buf;
2052 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2053 	}
2054 
2055 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2056 				clear_aptpl_metadata);
2057 	if (ret != 0)
2058 		return ret;
2059 	/*
2060 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2061 	 * on the passed buf to determine pr_aptpl_buf_len.
2062 	 */
2063 	ret = __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2064 	if (ret != 0)
2065 		return ret;
2066 
2067 	return ret;
2068 }
2069 
2070 static int core_scsi3_emulate_pro_register(
2071 	struct se_cmd *cmd,
2072 	u64 res_key,
2073 	u64 sa_res_key,
2074 	int aptpl,
2075 	int all_tg_pt,
2076 	int spec_i_pt,
2077 	int ignore_key)
2078 {
2079 	struct se_session *se_sess = cmd->se_sess;
2080 	struct se_device *dev = cmd->se_dev;
2081 	struct se_dev_entry *se_deve;
2082 	struct se_lun *se_lun = cmd->se_lun;
2083 	struct se_portal_group *se_tpg;
2084 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2085 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2086 	/* Used for APTPL metadata w/ UNREGISTER */
2087 	unsigned char *pr_aptpl_buf = NULL;
2088 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2089 	int pr_holder = 0, ret = 0, type;
2090 
2091 	if (!se_sess || !se_lun) {
2092 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2093 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2094 	}
2095 	se_tpg = se_sess->se_tpg;
2096 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2097 
2098 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2099 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2100 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2101 				PR_REG_ISID_LEN);
2102 		isid_ptr = &isid_buf[0];
2103 	}
2104 	/*
2105 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2106 	 */
2107 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2108 	if (!pr_reg_e) {
2109 		if (res_key) {
2110 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2111 				" for SA REGISTER, returning CONFLICT\n");
2112 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2113 		}
2114 		/*
2115 		 * Do nothing but return GOOD status.
2116 		 */
2117 		if (!sa_res_key)
2118 			return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2119 
2120 		if (!spec_i_pt) {
2121 			/*
2122 			 * Perform the Service Action REGISTER on the Initiator
2123 			 * Port Endpoint that the PRO was received from on the
2124 			 * Logical Unit of the SCSI device server.
2125 			 */
2126 			ret = core_scsi3_alloc_registration(cmd->se_dev,
2127 					se_sess->se_node_acl, se_deve, isid_ptr,
2128 					sa_res_key, all_tg_pt, aptpl,
2129 					ignore_key, 0);
2130 			if (ret != 0) {
2131 				pr_err("Unable to allocate"
2132 					" struct t10_pr_registration\n");
2133 				return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2134 			}
2135 		} else {
2136 			/*
2137 			 * Register both the Initiator port that received
2138 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2139 			 * TransportID from Parameter list and loop through
2140 			 * fabric dependent parameter list while calling
2141 			 * logic from of core_scsi3_alloc_registration() for
2142 			 * each TransportID provided SCSI Initiator Port/Device
2143 			 */
2144 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2145 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2146 			if (ret != 0)
2147 				return ret;
2148 		}
2149 		/*
2150 		 * Nothing left to do for the APTPL=0 case.
2151 		 */
2152 		if (!aptpl) {
2153 			pr_tmpl->pr_aptpl_active = 0;
2154 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2155 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2156 					" REGISTER\n");
2157 			return 0;
2158 		}
2159 		/*
2160 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2161 		 * update the APTPL metadata information using its
2162 		 * preallocated *pr_reg->pr_aptpl_buf.
2163 		 */
2164 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2165 				se_sess->se_node_acl, se_sess);
2166 
2167 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2168 				&pr_reg->pr_aptpl_buf[0],
2169 				pr_tmpl->pr_aptpl_buf_len);
2170 		if (!ret) {
2171 			pr_tmpl->pr_aptpl_active = 1;
2172 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2173 		}
2174 
2175 		core_scsi3_put_pr_reg(pr_reg);
2176 		return ret;
2177 	} else {
2178 		/*
2179 		 * Locate the existing *pr_reg via struct se_node_acl pointers
2180 		 */
2181 		pr_reg = pr_reg_e;
2182 		type = pr_reg->pr_res_type;
2183 
2184 		if (!ignore_key) {
2185 			if (res_key != pr_reg->pr_res_key) {
2186 				pr_err("SPC-3 PR REGISTER: Received"
2187 					" res_key: 0x%016Lx does not match"
2188 					" existing SA REGISTER res_key:"
2189 					" 0x%016Lx\n", res_key,
2190 					pr_reg->pr_res_key);
2191 				core_scsi3_put_pr_reg(pr_reg);
2192 				return PYX_TRANSPORT_RESERVATION_CONFLICT;
2193 			}
2194 		}
2195 		if (spec_i_pt) {
2196 			pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2197 				" set while sa_res_key=0\n");
2198 			core_scsi3_put_pr_reg(pr_reg);
2199 			return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2200 		}
2201 		/*
2202 		 * An existing ALL_TG_PT=1 registration being released
2203 		 * must also set ALL_TG_PT=1 in the incoming PROUT.
2204 		 */
2205 		if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2206 			pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2207 				" registration exists, but ALL_TG_PT=1 bit not"
2208 				" present in received PROUT\n");
2209 			core_scsi3_put_pr_reg(pr_reg);
2210 			return PYX_TRANSPORT_INVALID_CDB_FIELD;
2211 		}
2212 		/*
2213 		 * Allocate APTPL metadata buffer used for UNREGISTER ops
2214 		 */
2215 		if (aptpl) {
2216 			pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2217 						GFP_KERNEL);
2218 			if (!pr_aptpl_buf) {
2219 				pr_err("Unable to allocate"
2220 					" pr_aptpl_buf\n");
2221 				core_scsi3_put_pr_reg(pr_reg);
2222 				return PYX_TRANSPORT_LU_COMM_FAILURE;
2223 			}
2224 		}
2225 		/*
2226 		 * sa_res_key=0 Unregister Reservation Key for registered I_T
2227 		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2228 		 * Nexus.
2229 		 */
2230 		if (!sa_res_key) {
2231 			pr_holder = core_scsi3_check_implict_release(
2232 					cmd->se_dev, pr_reg);
2233 			if (pr_holder < 0) {
2234 				kfree(pr_aptpl_buf);
2235 				core_scsi3_put_pr_reg(pr_reg);
2236 				return PYX_TRANSPORT_RESERVATION_CONFLICT;
2237 			}
2238 
2239 			spin_lock(&pr_tmpl->registration_lock);
2240 			/*
2241 			 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2242 			 * and matching pr_res_key.
2243 			 */
2244 			if (pr_reg->pr_reg_all_tg_pt) {
2245 				list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2246 						&pr_tmpl->registration_list,
2247 						pr_reg_list) {
2248 
2249 					if (!pr_reg_p->pr_reg_all_tg_pt)
2250 						continue;
2251 
2252 					if (pr_reg_p->pr_res_key != res_key)
2253 						continue;
2254 
2255 					if (pr_reg == pr_reg_p)
2256 						continue;
2257 
2258 					if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2259 						   pr_reg_p->pr_reg_nacl->initiatorname))
2260 						continue;
2261 
2262 					__core_scsi3_free_registration(dev,
2263 							pr_reg_p, NULL, 0);
2264 				}
2265 			}
2266 			/*
2267 			 * Release the calling I_T Nexus registration now..
2268 			 */
2269 			__core_scsi3_free_registration(cmd->se_dev, pr_reg,
2270 							NULL, 1);
2271 			/*
2272 			 * From spc4r17, section 5.7.11.3 Unregistering
2273 			 *
2274 			 * If the persistent reservation is a registrants only
2275 			 * type, the device server shall establish a unit
2276 			 * attention condition for the initiator port associated
2277 			 * with every registered I_T nexus except for the I_T
2278 			 * nexus on which the PERSISTENT RESERVE OUT command was
2279 			 * received, with the additional sense code set to
2280 			 * RESERVATIONS RELEASED.
2281 			 */
2282 			if (pr_holder &&
2283 			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
2284 			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
2285 				list_for_each_entry(pr_reg_p,
2286 						&pr_tmpl->registration_list,
2287 						pr_reg_list) {
2288 
2289 					core_scsi3_ua_allocate(
2290 						pr_reg_p->pr_reg_nacl,
2291 						pr_reg_p->pr_res_mapped_lun,
2292 						0x2A,
2293 						ASCQ_2AH_RESERVATIONS_RELEASED);
2294 				}
2295 			}
2296 			spin_unlock(&pr_tmpl->registration_lock);
2297 
2298 			if (!aptpl) {
2299 				pr_tmpl->pr_aptpl_active = 0;
2300 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2301 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2302 						" for UNREGISTER\n");
2303 				return 0;
2304 			}
2305 
2306 			ret = core_scsi3_update_and_write_aptpl(dev,
2307 					&pr_aptpl_buf[0],
2308 					pr_tmpl->pr_aptpl_buf_len);
2309 			if (!ret) {
2310 				pr_tmpl->pr_aptpl_active = 1;
2311 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2312 						" for UNREGISTER\n");
2313 			}
2314 
2315 			kfree(pr_aptpl_buf);
2316 			return ret;
2317 		} else {
2318 			/*
2319 			 * Increment PRgeneration counter for struct se_device"
2320 			 * upon a successful REGISTER, see spc4r17 section 6.3.2
2321 			 * READ_KEYS service action.
2322 			 */
2323 			pr_reg->pr_res_generation = core_scsi3_pr_generation(
2324 							cmd->se_dev);
2325 			pr_reg->pr_res_key = sa_res_key;
2326 			pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2327 				" Key for %s to: 0x%016Lx PRgeneration:"
2328 				" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2329 				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2330 				pr_reg->pr_reg_nacl->initiatorname,
2331 				pr_reg->pr_res_key, pr_reg->pr_res_generation);
2332 
2333 			if (!aptpl) {
2334 				pr_tmpl->pr_aptpl_active = 0;
2335 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2336 				core_scsi3_put_pr_reg(pr_reg);
2337 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2338 						" for REGISTER\n");
2339 				return 0;
2340 			}
2341 
2342 			ret = core_scsi3_update_and_write_aptpl(dev,
2343 					&pr_aptpl_buf[0],
2344 					pr_tmpl->pr_aptpl_buf_len);
2345 			if (!ret) {
2346 				pr_tmpl->pr_aptpl_active = 1;
2347 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2348 						" for REGISTER\n");
2349 			}
2350 
2351 			kfree(pr_aptpl_buf);
2352 			core_scsi3_put_pr_reg(pr_reg);
2353 		}
2354 	}
2355 	return 0;
2356 }
2357 
2358 unsigned char *core_scsi3_pr_dump_type(int type)
2359 {
2360 	switch (type) {
2361 	case PR_TYPE_WRITE_EXCLUSIVE:
2362 		return "Write Exclusive Access";
2363 	case PR_TYPE_EXCLUSIVE_ACCESS:
2364 		return "Exclusive Access";
2365 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2366 		return "Write Exclusive Access, Registrants Only";
2367 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2368 		return "Exclusive Access, Registrants Only";
2369 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2370 		return "Write Exclusive Access, All Registrants";
2371 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2372 		return "Exclusive Access, All Registrants";
2373 	default:
2374 		break;
2375 	}
2376 
2377 	return "Unknown SPC-3 PR Type";
2378 }
2379 
2380 static int core_scsi3_pro_reserve(
2381 	struct se_cmd *cmd,
2382 	struct se_device *dev,
2383 	int type,
2384 	int scope,
2385 	u64 res_key)
2386 {
2387 	struct se_session *se_sess = cmd->se_sess;
2388 	struct se_dev_entry *se_deve;
2389 	struct se_lun *se_lun = cmd->se_lun;
2390 	struct se_portal_group *se_tpg;
2391 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2392 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2393 	char i_buf[PR_REG_ISID_ID_LEN];
2394 	int ret, prf_isid;
2395 
2396 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2397 
2398 	if (!se_sess || !se_lun) {
2399 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2400 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2401 	}
2402 	se_tpg = se_sess->se_tpg;
2403 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2404 	/*
2405 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2406 	 */
2407 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2408 				se_sess);
2409 	if (!pr_reg) {
2410 		pr_err("SPC-3 PR: Unable to locate"
2411 			" PR_REGISTERED *pr_reg for RESERVE\n");
2412 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2413 	}
2414 	/*
2415 	 * From spc4r17 Section 5.7.9: Reserving:
2416 	 *
2417 	 * An application client creates a persistent reservation by issuing
2418 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2419 	 * a registered I_T nexus with the following parameters:
2420 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2421 	 * 	 registered with the logical unit for the I_T nexus; and
2422 	 */
2423 	if (res_key != pr_reg->pr_res_key) {
2424 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2425 			" does not match existing SA REGISTER res_key:"
2426 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2427 		core_scsi3_put_pr_reg(pr_reg);
2428 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2429 	}
2430 	/*
2431 	 * From spc4r17 Section 5.7.9: Reserving:
2432 	 *
2433 	 * From above:
2434 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2435 	 *     being created.
2436 	 *
2437 	 * Only one persistent reservation is allowed at a time per logical unit
2438 	 * and that persistent reservation has a scope of LU_SCOPE.
2439 	 */
2440 	if (scope != PR_SCOPE_LU_SCOPE) {
2441 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2442 		core_scsi3_put_pr_reg(pr_reg);
2443 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2444 	}
2445 	/*
2446 	 * See if we have an existing PR reservation holder pointer at
2447 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2448 	 * *pr_res_holder.
2449 	 */
2450 	spin_lock(&dev->dev_reservation_lock);
2451 	pr_res_holder = dev->dev_pr_res_holder;
2452 	if ((pr_res_holder)) {
2453 		/*
2454 		 * From spc4r17 Section 5.7.9: Reserving:
2455 		 *
2456 		 * If the device server receives a PERSISTENT RESERVE OUT
2457 		 * command from an I_T nexus other than a persistent reservation
2458 		 * holder (see 5.7.10) that attempts to create a persistent
2459 		 * reservation when a persistent reservation already exists for
2460 		 * the logical unit, then the command shall be completed with
2461 		 * RESERVATION CONFLICT status.
2462 		 */
2463 		if (pr_res_holder != pr_reg) {
2464 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2465 			pr_err("SPC-3 PR: Attempted RESERVE from"
2466 				" [%s]: %s while reservation already held by"
2467 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2468 				cmd->se_tfo->get_fabric_name(),
2469 				se_sess->se_node_acl->initiatorname,
2470 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2471 				pr_res_holder->pr_reg_nacl->initiatorname);
2472 
2473 			spin_unlock(&dev->dev_reservation_lock);
2474 			core_scsi3_put_pr_reg(pr_reg);
2475 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2476 		}
2477 		/*
2478 		 * From spc4r17 Section 5.7.9: Reserving:
2479 		 *
2480 		 * If a persistent reservation holder attempts to modify the
2481 		 * type or scope of an existing persistent reservation, the
2482 		 * command shall be completed with RESERVATION CONFLICT status.
2483 		 */
2484 		if ((pr_res_holder->pr_res_type != type) ||
2485 		    (pr_res_holder->pr_res_scope != scope)) {
2486 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2487 			pr_err("SPC-3 PR: Attempted RESERVE from"
2488 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2489 				" while reservation already held by [%s]: %s,"
2490 				" returning RESERVATION_CONFLICT\n",
2491 				cmd->se_tfo->get_fabric_name(),
2492 				se_sess->se_node_acl->initiatorname,
2493 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2494 				pr_res_holder->pr_reg_nacl->initiatorname);
2495 
2496 			spin_unlock(&dev->dev_reservation_lock);
2497 			core_scsi3_put_pr_reg(pr_reg);
2498 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2499 		}
2500 		/*
2501 		 * From spc4r17 Section 5.7.9: Reserving:
2502 		 *
2503 		 * If the device server receives a PERSISTENT RESERVE OUT
2504 		 * command with RESERVE service action where the TYPE field and
2505 		 * the SCOPE field contain the same values as the existing type
2506 		 * and scope from a persistent reservation holder, it shall not
2507 		 * make any change to the existing persistent reservation and
2508 		 * shall completethe command with GOOD status.
2509 		 */
2510 		spin_unlock(&dev->dev_reservation_lock);
2511 		core_scsi3_put_pr_reg(pr_reg);
2512 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2513 	}
2514 	/*
2515 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2516 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2517 	 */
2518 	pr_reg->pr_res_scope = scope;
2519 	pr_reg->pr_res_type = type;
2520 	pr_reg->pr_res_holder = 1;
2521 	dev->dev_pr_res_holder = pr_reg;
2522 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2523 				PR_REG_ISID_ID_LEN);
2524 
2525 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2526 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2527 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2528 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2529 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2530 			cmd->se_tfo->get_fabric_name(),
2531 			se_sess->se_node_acl->initiatorname,
2532 			(prf_isid) ? &i_buf[0] : "");
2533 	spin_unlock(&dev->dev_reservation_lock);
2534 
2535 	if (pr_tmpl->pr_aptpl_active) {
2536 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2537 				&pr_reg->pr_aptpl_buf[0],
2538 				pr_tmpl->pr_aptpl_buf_len);
2539 		if (!ret)
2540 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2541 					" for RESERVE\n");
2542 	}
2543 
2544 	core_scsi3_put_pr_reg(pr_reg);
2545 	return 0;
2546 }
2547 
2548 static int core_scsi3_emulate_pro_reserve(
2549 	struct se_cmd *cmd,
2550 	int type,
2551 	int scope,
2552 	u64 res_key)
2553 {
2554 	struct se_device *dev = cmd->se_dev;
2555 	int ret = 0;
2556 
2557 	switch (type) {
2558 	case PR_TYPE_WRITE_EXCLUSIVE:
2559 	case PR_TYPE_EXCLUSIVE_ACCESS:
2560 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2561 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2562 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2563 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2564 		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
2565 		break;
2566 	default:
2567 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2568 			" 0x%02x\n", type);
2569 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
2570 	}
2571 
2572 	return ret;
2573 }
2574 
2575 /*
2576  * Called with struct se_device->dev_reservation_lock held.
2577  */
2578 static void __core_scsi3_complete_pro_release(
2579 	struct se_device *dev,
2580 	struct se_node_acl *se_nacl,
2581 	struct t10_pr_registration *pr_reg,
2582 	int explict)
2583 {
2584 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2585 	char i_buf[PR_REG_ISID_ID_LEN];
2586 	int prf_isid;
2587 
2588 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2589 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2590 				PR_REG_ISID_ID_LEN);
2591 	/*
2592 	 * Go ahead and release the current PR reservation holder.
2593 	 */
2594 	dev->dev_pr_res_holder = NULL;
2595 
2596 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2597 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2598 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2599 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2600 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2601 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2602 		tfo->get_fabric_name(), se_nacl->initiatorname,
2603 		(prf_isid) ? &i_buf[0] : "");
2604 	/*
2605 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2606 	 */
2607 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2608 }
2609 
2610 static int core_scsi3_emulate_pro_release(
2611 	struct se_cmd *cmd,
2612 	int type,
2613 	int scope,
2614 	u64 res_key)
2615 {
2616 	struct se_device *dev = cmd->se_dev;
2617 	struct se_session *se_sess = cmd->se_sess;
2618 	struct se_lun *se_lun = cmd->se_lun;
2619 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2620 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2621 	int ret, all_reg = 0;
2622 
2623 	if (!se_sess || !se_lun) {
2624 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2625 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2626 	}
2627 	/*
2628 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2629 	 */
2630 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2631 	if (!pr_reg) {
2632 		pr_err("SPC-3 PR: Unable to locate"
2633 			" PR_REGISTERED *pr_reg for RELEASE\n");
2634 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2635 	}
2636 	/*
2637 	 * From spc4r17 Section 5.7.11.2 Releasing:
2638 	 *
2639 	 * If there is no persistent reservation or in response to a persistent
2640 	 * reservation release request from a registered I_T nexus that is not a
2641 	 * persistent reservation holder (see 5.7.10), the device server shall
2642 	 * do the following:
2643 	 *
2644 	 *     a) Not release the persistent reservation, if any;
2645 	 *     b) Not remove any registrations; and
2646 	 *     c) Complete the command with GOOD status.
2647 	 */
2648 	spin_lock(&dev->dev_reservation_lock);
2649 	pr_res_holder = dev->dev_pr_res_holder;
2650 	if (!pr_res_holder) {
2651 		/*
2652 		 * No persistent reservation, return GOOD status.
2653 		 */
2654 		spin_unlock(&dev->dev_reservation_lock);
2655 		core_scsi3_put_pr_reg(pr_reg);
2656 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2657 	}
2658 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2659 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2660 		all_reg = 1;
2661 
2662 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2663 		/*
2664 		 * Non 'All Registrants' PR Type cases..
2665 		 * Release request from a registered I_T nexus that is not a
2666 		 * persistent reservation holder. return GOOD status.
2667 		 */
2668 		spin_unlock(&dev->dev_reservation_lock);
2669 		core_scsi3_put_pr_reg(pr_reg);
2670 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2671 	}
2672 	/*
2673 	 * From spc4r17 Section 5.7.11.2 Releasing:
2674 	 *
2675 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2676 	 * release a persistent reservation.
2677 	 *
2678 	 * An application client releases the persistent reservation by issuing
2679 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2680 	 * an I_T nexus that is a persistent reservation holder with the
2681 	 * following parameters:
2682 	 *
2683 	 *     a) RESERVATION KEY field set to the value of the reservation key
2684 	 *	  that is registered with the logical unit for the I_T nexus;
2685 	 */
2686 	if (res_key != pr_reg->pr_res_key) {
2687 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2688 			" does not match existing SA REGISTER res_key:"
2689 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2690 		spin_unlock(&dev->dev_reservation_lock);
2691 		core_scsi3_put_pr_reg(pr_reg);
2692 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2693 	}
2694 	/*
2695 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2696 	 *
2697 	 * b) TYPE field and SCOPE field set to match the persistent
2698 	 *    reservation being released.
2699 	 */
2700 	if ((pr_res_holder->pr_res_type != type) ||
2701 	    (pr_res_holder->pr_res_scope != scope)) {
2702 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2703 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2704 			" reservation from [%s]: %s with different TYPE "
2705 			"and/or SCOPE  while reservation already held by"
2706 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2707 			cmd->se_tfo->get_fabric_name(),
2708 			se_sess->se_node_acl->initiatorname,
2709 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2710 			pr_res_holder->pr_reg_nacl->initiatorname);
2711 
2712 		spin_unlock(&dev->dev_reservation_lock);
2713 		core_scsi3_put_pr_reg(pr_reg);
2714 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2715 	}
2716 	/*
2717 	 * In response to a persistent reservation release request from the
2718 	 * persistent reservation holder the device server shall perform a
2719 	 * release by doing the following as an uninterrupted series of actions:
2720 	 * a) Release the persistent reservation;
2721 	 * b) Not remove any registration(s);
2722 	 * c) If the released persistent reservation is a registrants only type
2723 	 * or all registrants type persistent reservation,
2724 	 *    the device server shall establish a unit attention condition for
2725 	 *    the initiator port associated with every regis-
2726 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2727 	 *    RESERVE OUT command with RELEASE service action was received,
2728 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2729 	 * d) If the persistent reservation is of any other type, the device
2730 	 *    server shall not establish a unit attention condition.
2731 	 */
2732 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2733 			pr_reg, 1);
2734 
2735 	spin_unlock(&dev->dev_reservation_lock);
2736 
2737 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2738 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2739 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2740 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2741 		/*
2742 		 * If no UNIT ATTENTION conditions will be established for
2743 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2744 		 * go ahead and check for APTPL=1 update+write below
2745 		 */
2746 		goto write_aptpl;
2747 	}
2748 
2749 	spin_lock(&pr_tmpl->registration_lock);
2750 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2751 			pr_reg_list) {
2752 		/*
2753 		 * Do not establish a UNIT ATTENTION condition
2754 		 * for the calling I_T Nexus
2755 		 */
2756 		if (pr_reg_p == pr_reg)
2757 			continue;
2758 
2759 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2760 				pr_reg_p->pr_res_mapped_lun,
2761 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2762 	}
2763 	spin_unlock(&pr_tmpl->registration_lock);
2764 
2765 write_aptpl:
2766 	if (pr_tmpl->pr_aptpl_active) {
2767 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2768 				&pr_reg->pr_aptpl_buf[0],
2769 				pr_tmpl->pr_aptpl_buf_len);
2770 		if (!ret)
2771 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2772 	}
2773 
2774 	core_scsi3_put_pr_reg(pr_reg);
2775 	return 0;
2776 }
2777 
2778 static int core_scsi3_emulate_pro_clear(
2779 	struct se_cmd *cmd,
2780 	u64 res_key)
2781 {
2782 	struct se_device *dev = cmd->se_dev;
2783 	struct se_node_acl *pr_reg_nacl;
2784 	struct se_session *se_sess = cmd->se_sess;
2785 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2786 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2787 	u32 pr_res_mapped_lun = 0;
2788 	int calling_it_nexus = 0;
2789 	/*
2790 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2791 	 */
2792 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2793 			se_sess->se_node_acl, se_sess);
2794 	if (!pr_reg_n) {
2795 		pr_err("SPC-3 PR: Unable to locate"
2796 			" PR_REGISTERED *pr_reg for CLEAR\n");
2797 			return PYX_TRANSPORT_LU_COMM_FAILURE;
2798 	}
2799 	/*
2800 	 * From spc4r17 section 5.7.11.6, Clearing:
2801 	 *
2802 	 * Any application client may release the persistent reservation and
2803 	 * remove all registrations from a device server by issuing a
2804 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2805 	 * registered I_T nexus with the following parameter:
2806 	 *
2807 	 *	a) RESERVATION KEY field set to the value of the reservation key
2808 	 * 	   that is registered with the logical unit for the I_T nexus.
2809 	 */
2810 	if (res_key != pr_reg_n->pr_res_key) {
2811 		pr_err("SPC-3 PR REGISTER: Received"
2812 			" res_key: 0x%016Lx does not match"
2813 			" existing SA REGISTER res_key:"
2814 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2815 		core_scsi3_put_pr_reg(pr_reg_n);
2816 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2817 	}
2818 	/*
2819 	 * a) Release the persistent reservation, if any;
2820 	 */
2821 	spin_lock(&dev->dev_reservation_lock);
2822 	pr_res_holder = dev->dev_pr_res_holder;
2823 	if (pr_res_holder) {
2824 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2825 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2826 			pr_res_holder, 0);
2827 	}
2828 	spin_unlock(&dev->dev_reservation_lock);
2829 	/*
2830 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2831 	 */
2832 	spin_lock(&pr_tmpl->registration_lock);
2833 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2834 			&pr_tmpl->registration_list, pr_reg_list) {
2835 
2836 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2837 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2838 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2839 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2840 					calling_it_nexus);
2841 		/*
2842 		 * e) Establish a unit attention condition for the initiator
2843 		 *    port associated with every registered I_T nexus other
2844 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2845 		 *    command with CLEAR service action was received, with the
2846 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2847 		 */
2848 		if (!calling_it_nexus)
2849 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2850 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2851 	}
2852 	spin_unlock(&pr_tmpl->registration_lock);
2853 
2854 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2855 		cmd->se_tfo->get_fabric_name());
2856 
2857 	if (pr_tmpl->pr_aptpl_active) {
2858 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2859 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2860 				" for CLEAR\n");
2861 	}
2862 
2863 	core_scsi3_pr_generation(dev);
2864 	return 0;
2865 }
2866 
2867 /*
2868  * Called with struct se_device->dev_reservation_lock held.
2869  */
2870 static void __core_scsi3_complete_pro_preempt(
2871 	struct se_device *dev,
2872 	struct t10_pr_registration *pr_reg,
2873 	struct list_head *preempt_and_abort_list,
2874 	int type,
2875 	int scope,
2876 	int abort)
2877 {
2878 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2879 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2880 	char i_buf[PR_REG_ISID_ID_LEN];
2881 	int prf_isid;
2882 
2883 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2884 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2885 				PR_REG_ISID_ID_LEN);
2886 	/*
2887 	 * Do an implict RELEASE of the existing reservation.
2888 	 */
2889 	if (dev->dev_pr_res_holder)
2890 		__core_scsi3_complete_pro_release(dev, nacl,
2891 				dev->dev_pr_res_holder, 0);
2892 
2893 	dev->dev_pr_res_holder = pr_reg;
2894 	pr_reg->pr_res_holder = 1;
2895 	pr_reg->pr_res_type = type;
2896 	pr_reg->pr_res_scope = scope;
2897 
2898 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2899 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2900 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2901 		core_scsi3_pr_dump_type(type),
2902 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2903 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2904 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2905 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2906 	/*
2907 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2908 	 * struct t10_pr_registration to the list that will be compared
2909 	 * against received CDBs..
2910 	 */
2911 	if (preempt_and_abort_list)
2912 		list_add_tail(&pr_reg->pr_reg_abort_list,
2913 				preempt_and_abort_list);
2914 }
2915 
2916 static void core_scsi3_release_preempt_and_abort(
2917 	struct list_head *preempt_and_abort_list,
2918 	struct t10_pr_registration *pr_reg_holder)
2919 {
2920 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2921 
2922 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2923 				pr_reg_abort_list) {
2924 
2925 		list_del(&pr_reg->pr_reg_abort_list);
2926 		if (pr_reg_holder == pr_reg)
2927 			continue;
2928 		if (pr_reg->pr_res_holder) {
2929 			pr_warn("pr_reg->pr_res_holder still set\n");
2930 			continue;
2931 		}
2932 
2933 		pr_reg->pr_reg_deve = NULL;
2934 		pr_reg->pr_reg_nacl = NULL;
2935 		kfree(pr_reg->pr_aptpl_buf);
2936 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2937 	}
2938 }
2939 
2940 int core_scsi3_check_cdb_abort_and_preempt(
2941 	struct list_head *preempt_and_abort_list,
2942 	struct se_cmd *cmd)
2943 {
2944 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2945 
2946 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2947 				pr_reg_abort_list) {
2948 		if (pr_reg->pr_res_key == cmd->pr_res_key)
2949 			return 0;
2950 	}
2951 
2952 	return 1;
2953 }
2954 
2955 static int core_scsi3_pro_preempt(
2956 	struct se_cmd *cmd,
2957 	int type,
2958 	int scope,
2959 	u64 res_key,
2960 	u64 sa_res_key,
2961 	int abort)
2962 {
2963 	struct se_device *dev = cmd->se_dev;
2964 	struct se_dev_entry *se_deve;
2965 	struct se_node_acl *pr_reg_nacl;
2966 	struct se_session *se_sess = cmd->se_sess;
2967 	struct list_head preempt_and_abort_list;
2968 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2969 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2970 	u32 pr_res_mapped_lun = 0;
2971 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
2972 	int prh_type = 0, prh_scope = 0, ret;
2973 
2974 	if (!se_sess)
2975 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2976 
2977 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2978 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2979 				se_sess);
2980 	if (!pr_reg_n) {
2981 		pr_err("SPC-3 PR: Unable to locate"
2982 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2983 			(abort) ? "_AND_ABORT" : "");
2984 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2985 	}
2986 	if (pr_reg_n->pr_res_key != res_key) {
2987 		core_scsi3_put_pr_reg(pr_reg_n);
2988 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2989 	}
2990 	if (scope != PR_SCOPE_LU_SCOPE) {
2991 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2992 		core_scsi3_put_pr_reg(pr_reg_n);
2993 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2994 	}
2995 	INIT_LIST_HEAD(&preempt_and_abort_list);
2996 
2997 	spin_lock(&dev->dev_reservation_lock);
2998 	pr_res_holder = dev->dev_pr_res_holder;
2999 	if (pr_res_holder &&
3000 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3001 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
3002 		all_reg = 1;
3003 
3004 	if (!all_reg && !sa_res_key) {
3005 		spin_unlock(&dev->dev_reservation_lock);
3006 		core_scsi3_put_pr_reg(pr_reg_n);
3007 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3008 	}
3009 	/*
3010 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
3011 	 *
3012 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
3013 	 * persistent reservation holder or there is no persistent reservation
3014 	 * holder (i.e., there is no persistent reservation), then the device
3015 	 * server shall perform a preempt by doing the following in an
3016 	 * uninterrupted series of actions. (See below..)
3017 	 */
3018 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
3019 		/*
3020 		 * No existing or SA Reservation Key matching reservations..
3021 		 *
3022 		 * PROUT SA PREEMPT with All Registrant type reservations are
3023 		 * allowed to be processed without a matching SA Reservation Key
3024 		 */
3025 		spin_lock(&pr_tmpl->registration_lock);
3026 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3027 				&pr_tmpl->registration_list, pr_reg_list) {
3028 			/*
3029 			 * Removing of registrations in non all registrants
3030 			 * type reservations without a matching SA reservation
3031 			 * key.
3032 			 *
3033 			 * a) Remove the registrations for all I_T nexuses
3034 			 *    specified by the SERVICE ACTION RESERVATION KEY
3035 			 *    field;
3036 			 * b) Ignore the contents of the SCOPE and TYPE fields;
3037 			 * c) Process tasks as defined in 5.7.1; and
3038 			 * d) Establish a unit attention condition for the
3039 			 *    initiator port associated with every I_T nexus
3040 			 *    that lost its registration other than the I_T
3041 			 *    nexus on which the PERSISTENT RESERVE OUT command
3042 			 *    was received, with the additional sense code set
3043 			 *    to REGISTRATIONS PREEMPTED.
3044 			 */
3045 			if (!all_reg) {
3046 				if (pr_reg->pr_res_key != sa_res_key)
3047 					continue;
3048 
3049 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3050 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3051 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3052 				__core_scsi3_free_registration(dev, pr_reg,
3053 					(abort) ? &preempt_and_abort_list :
3054 						NULL, calling_it_nexus);
3055 				released_regs++;
3056 			} else {
3057 				/*
3058 				 * Case for any existing all registrants type
3059 				 * reservation, follow logic in spc4r17 section
3060 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
3061 				 *
3062 				 * For a ZERO SA Reservation key, release
3063 				 * all other registrations and do an implict
3064 				 * release of active persistent reservation.
3065 				 *
3066 				 * For a non-ZERO SA Reservation key, only
3067 				 * release the matching reservation key from
3068 				 * registrations.
3069 				 */
3070 				if ((sa_res_key) &&
3071 				     (pr_reg->pr_res_key != sa_res_key))
3072 					continue;
3073 
3074 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3075 				if (calling_it_nexus)
3076 					continue;
3077 
3078 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3079 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3080 				__core_scsi3_free_registration(dev, pr_reg,
3081 					(abort) ? &preempt_and_abort_list :
3082 						NULL, 0);
3083 				released_regs++;
3084 			}
3085 			if (!calling_it_nexus)
3086 				core_scsi3_ua_allocate(pr_reg_nacl,
3087 					pr_res_mapped_lun, 0x2A,
3088 					ASCQ_2AH_RESERVATIONS_PREEMPTED);
3089 		}
3090 		spin_unlock(&pr_tmpl->registration_lock);
3091 		/*
3092 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3093 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3094 		 * RESERVATION KEY field to a value that does not match any
3095 		 * registered reservation key, then the device server shall
3096 		 * complete the command with RESERVATION CONFLICT status.
3097 		 */
3098 		if (!released_regs) {
3099 			spin_unlock(&dev->dev_reservation_lock);
3100 			core_scsi3_put_pr_reg(pr_reg_n);
3101 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
3102 		}
3103 		/*
3104 		 * For an existing all registrants type reservation
3105 		 * with a zero SA rservation key, preempt the existing
3106 		 * reservation with the new PR type and scope.
3107 		 */
3108 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3109 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3110 				(abort) ? &preempt_and_abort_list : NULL,
3111 				type, scope, abort);
3112 
3113 			if (abort)
3114 				core_scsi3_release_preempt_and_abort(
3115 					&preempt_and_abort_list, pr_reg_n);
3116 		}
3117 		spin_unlock(&dev->dev_reservation_lock);
3118 
3119 		if (pr_tmpl->pr_aptpl_active) {
3120 			ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3121 					&pr_reg_n->pr_aptpl_buf[0],
3122 					pr_tmpl->pr_aptpl_buf_len);
3123 			if (!ret)
3124 				pr_debug("SPC-3 PR: Updated APTPL"
3125 					" metadata for  PREEMPT%s\n", (abort) ?
3126 					"_AND_ABORT" : "");
3127 		}
3128 
3129 		core_scsi3_put_pr_reg(pr_reg_n);
3130 		core_scsi3_pr_generation(cmd->se_dev);
3131 		return 0;
3132 	}
3133 	/*
3134 	 * The PREEMPTing SA reservation key matches that of the
3135 	 * existing persistent reservation, first, we check if
3136 	 * we are preempting our own reservation.
3137 	 * From spc4r17, section 5.7.11.4.3 Preempting
3138 	 * persistent reservations and registration handling
3139 	 *
3140 	 * If an all registrants persistent reservation is not
3141 	 * present, it is not an error for the persistent
3142 	 * reservation holder to preempt itself (i.e., a
3143 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3144 	 * or a PREEMPT AND ABORT service action with the
3145 	 * SERVICE ACTION RESERVATION KEY value equal to the
3146 	 * persistent reservation holder's reservation key that
3147 	 * is received from the persistent reservation holder).
3148 	 * In that case, the device server shall establish the
3149 	 * new persistent reservation and maintain the
3150 	 * registration.
3151 	 */
3152 	prh_type = pr_res_holder->pr_res_type;
3153 	prh_scope = pr_res_holder->pr_res_scope;
3154 	/*
3155 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3156 	 * persistent reservation holder (see 5.7.10), the device
3157 	 * server shall perform a preempt by doing the following as
3158 	 * an uninterrupted series of actions:
3159 	 *
3160 	 * a) Release the persistent reservation for the holder
3161 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3162 	 */
3163 	if (pr_reg_n != pr_res_holder)
3164 		__core_scsi3_complete_pro_release(dev,
3165 				pr_res_holder->pr_reg_nacl,
3166 				dev->dev_pr_res_holder, 0);
3167 	/*
3168 	 * b) Remove the registrations for all I_T nexuses identified
3169 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3170 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3171 	 *    OUT command. If an all registrants persistent reservation
3172 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3173 	 *    is set to zero, then all registrations shall be removed
3174 	 *    except for that of the I_T nexus that is being used for
3175 	 *    the PERSISTENT RESERVE OUT command;
3176 	 */
3177 	spin_lock(&pr_tmpl->registration_lock);
3178 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3179 			&pr_tmpl->registration_list, pr_reg_list) {
3180 
3181 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3182 		if (calling_it_nexus)
3183 			continue;
3184 
3185 		if (pr_reg->pr_res_key != sa_res_key)
3186 			continue;
3187 
3188 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3189 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3190 		__core_scsi3_free_registration(dev, pr_reg,
3191 				(abort) ? &preempt_and_abort_list : NULL,
3192 				calling_it_nexus);
3193 		/*
3194 		 * e) Establish a unit attention condition for the initiator
3195 		 *    port associated with every I_T nexus that lost its
3196 		 *    persistent reservation and/or registration, with the
3197 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3198 		 */
3199 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3200 				ASCQ_2AH_RESERVATIONS_PREEMPTED);
3201 	}
3202 	spin_unlock(&pr_tmpl->registration_lock);
3203 	/*
3204 	 * c) Establish a persistent reservation for the preempting
3205 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3206 	 */
3207 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3208 			(abort) ? &preempt_and_abort_list : NULL,
3209 			type, scope, abort);
3210 	/*
3211 	 * d) Process tasks as defined in 5.7.1;
3212 	 * e) See above..
3213 	 * f) If the type or scope has changed, then for every I_T nexus
3214 	 *    whose reservation key was not removed, except for the I_T
3215 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3216 	 *    received, the device server shall establish a unit
3217 	 *    attention condition for the initiator port associated with
3218 	 *    that I_T nexus, with the additional sense code set to
3219 	 *    RESERVATIONS RELEASED. If the type or scope have not
3220 	 *    changed, then no unit attention condition(s) shall be
3221 	 *    established for this reason.
3222 	 */
3223 	if ((prh_type != type) || (prh_scope != scope)) {
3224 		spin_lock(&pr_tmpl->registration_lock);
3225 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3226 				&pr_tmpl->registration_list, pr_reg_list) {
3227 
3228 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3229 			if (calling_it_nexus)
3230 				continue;
3231 
3232 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3233 					pr_reg->pr_res_mapped_lun, 0x2A,
3234 					ASCQ_2AH_RESERVATIONS_RELEASED);
3235 		}
3236 		spin_unlock(&pr_tmpl->registration_lock);
3237 	}
3238 	spin_unlock(&dev->dev_reservation_lock);
3239 	/*
3240 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3241 	 * All received CDBs for the matching existing reservation and
3242 	 * registrations undergo ABORT_TASK logic.
3243 	 *
3244 	 * From there, core_scsi3_release_preempt_and_abort() will
3245 	 * release every registration in the list (which have already
3246 	 * been removed from the primary pr_reg list), except the
3247 	 * new persistent reservation holder, the calling Initiator Port.
3248 	 */
3249 	if (abort) {
3250 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3251 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3252 						pr_reg_n);
3253 	}
3254 
3255 	if (pr_tmpl->pr_aptpl_active) {
3256 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3257 				&pr_reg_n->pr_aptpl_buf[0],
3258 				pr_tmpl->pr_aptpl_buf_len);
3259 		if (!ret)
3260 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3261 				"%s\n", (abort) ? "_AND_ABORT" : "");
3262 	}
3263 
3264 	core_scsi3_put_pr_reg(pr_reg_n);
3265 	core_scsi3_pr_generation(cmd->se_dev);
3266 	return 0;
3267 }
3268 
3269 static int core_scsi3_emulate_pro_preempt(
3270 	struct se_cmd *cmd,
3271 	int type,
3272 	int scope,
3273 	u64 res_key,
3274 	u64 sa_res_key,
3275 	int abort)
3276 {
3277 	int ret = 0;
3278 
3279 	switch (type) {
3280 	case PR_TYPE_WRITE_EXCLUSIVE:
3281 	case PR_TYPE_EXCLUSIVE_ACCESS:
3282 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3283 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3284 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3285 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3286 		ret = core_scsi3_pro_preempt(cmd, type, scope,
3287 				res_key, sa_res_key, abort);
3288 		break;
3289 	default:
3290 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3291 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3292 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3293 	}
3294 
3295 	return ret;
3296 }
3297 
3298 
3299 static int core_scsi3_emulate_pro_register_and_move(
3300 	struct se_cmd *cmd,
3301 	u64 res_key,
3302 	u64 sa_res_key,
3303 	int aptpl,
3304 	int unreg)
3305 {
3306 	struct se_session *se_sess = cmd->se_sess;
3307 	struct se_device *dev = cmd->se_dev;
3308 	struct se_dev_entry *se_deve, *dest_se_deve = NULL;
3309 	struct se_lun *se_lun = cmd->se_lun;
3310 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3311 	struct se_port *se_port;
3312 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3313 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3314 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3315 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3316 	unsigned char *buf;
3317 	unsigned char *initiator_str;
3318 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3319 	u32 tid_len, tmp_tid_len;
3320 	int new_reg = 0, type, scope, ret, matching_iname, prf_isid;
3321 	unsigned short rtpi;
3322 	unsigned char proto_ident;
3323 
3324 	if (!se_sess || !se_lun) {
3325 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3326 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3327 	}
3328 	memset(dest_iport, 0, 64);
3329 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3330 	se_tpg = se_sess->se_tpg;
3331 	tf_ops = se_tpg->se_tpg_tfo;
3332 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
3333 	/*
3334 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3335 	 *	Register behaviors for a REGISTER AND MOVE service action
3336 	 *
3337 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3338 	 */
3339 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3340 				se_sess);
3341 	if (!pr_reg) {
3342 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3343 			" *pr_reg for REGISTER_AND_MOVE\n");
3344 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3345 	}
3346 	/*
3347 	 * The provided reservation key much match the existing reservation key
3348 	 * provided during this initiator's I_T nexus registration.
3349 	 */
3350 	if (res_key != pr_reg->pr_res_key) {
3351 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3352 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3353 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3354 		core_scsi3_put_pr_reg(pr_reg);
3355 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
3356 	}
3357 	/*
3358 	 * The service active reservation key needs to be non zero
3359 	 */
3360 	if (!sa_res_key) {
3361 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3362 			" sa_res_key\n");
3363 		core_scsi3_put_pr_reg(pr_reg);
3364 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3365 	}
3366 
3367 	/*
3368 	 * Determine the Relative Target Port Identifier where the reservation
3369 	 * will be moved to for the TransportID containing SCSI initiator WWN
3370 	 * information.
3371 	 */
3372 	buf = transport_kmap_first_data_page(cmd);
3373 	rtpi = (buf[18] & 0xff) << 8;
3374 	rtpi |= buf[19] & 0xff;
3375 	tid_len = (buf[20] & 0xff) << 24;
3376 	tid_len |= (buf[21] & 0xff) << 16;
3377 	tid_len |= (buf[22] & 0xff) << 8;
3378 	tid_len |= buf[23] & 0xff;
3379 	transport_kunmap_first_data_page(cmd);
3380 	buf = NULL;
3381 
3382 	if ((tid_len + 24) != cmd->data_length) {
3383 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3384 			" does not equal CDB data_length: %u\n", tid_len,
3385 			cmd->data_length);
3386 		core_scsi3_put_pr_reg(pr_reg);
3387 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3388 	}
3389 
3390 	spin_lock(&dev->se_port_lock);
3391 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3392 		if (se_port->sep_rtpi != rtpi)
3393 			continue;
3394 		dest_se_tpg = se_port->sep_tpg;
3395 		if (!dest_se_tpg)
3396 			continue;
3397 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3398 		if (!dest_tf_ops)
3399 			continue;
3400 
3401 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3402 		smp_mb__after_atomic_inc();
3403 		spin_unlock(&dev->se_port_lock);
3404 
3405 		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
3406 		if (ret != 0) {
3407 			pr_err("core_scsi3_tpg_depend_item() failed"
3408 				" for dest_se_tpg\n");
3409 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3410 			smp_mb__after_atomic_dec();
3411 			core_scsi3_put_pr_reg(pr_reg);
3412 			return PYX_TRANSPORT_LU_COMM_FAILURE;
3413 		}
3414 
3415 		spin_lock(&dev->se_port_lock);
3416 		break;
3417 	}
3418 	spin_unlock(&dev->se_port_lock);
3419 
3420 	if (!dest_se_tpg || !dest_tf_ops) {
3421 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3422 			" fabric ops from Relative Target Port Identifier:"
3423 			" %hu\n", rtpi);
3424 		core_scsi3_put_pr_reg(pr_reg);
3425 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3426 	}
3427 
3428 	buf = transport_kmap_first_data_page(cmd);
3429 	proto_ident = (buf[24] & 0x0f);
3430 #if 0
3431 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3432 			" 0x%02x\n", proto_ident);
3433 #endif
3434 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3435 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3436 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3437 			" from fabric: %s\n", proto_ident,
3438 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3439 			dest_tf_ops->get_fabric_name());
3440 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3441 		goto out;
3442 	}
3443 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3444 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3445 			" containg a valid tpg_parse_pr_out_transport_id"
3446 			" function pointer\n");
3447 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3448 		goto out;
3449 	}
3450 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3451 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3452 	if (!initiator_str) {
3453 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3454 			" initiator_str from Transport ID\n");
3455 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3456 		goto out;
3457 	}
3458 
3459 	transport_kunmap_first_data_page(cmd);
3460 	buf = NULL;
3461 
3462 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3463 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3464 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3465 		iport_ptr : "");
3466 	/*
3467 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3468 	 * action specifies a TransportID that is the same as the initiator port
3469 	 * of the I_T nexus for the command received, then the command shall
3470 	 * be terminated with CHECK CONDITION status, with the sense key set to
3471 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3472 	 * IN PARAMETER LIST.
3473 	 */
3474 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3475 	matching_iname = (!strcmp(initiator_str,
3476 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3477 	if (!matching_iname)
3478 		goto after_iport_check;
3479 
3480 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3481 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3482 			" matches: %s on received I_T Nexus\n", initiator_str,
3483 			pr_reg_nacl->initiatorname);
3484 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3485 		goto out;
3486 	}
3487 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3488 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3489 			" matches: %s %s on received I_T Nexus\n",
3490 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3491 			pr_reg->pr_reg_isid);
3492 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3493 		goto out;
3494 	}
3495 after_iport_check:
3496 	/*
3497 	 * Locate the destination struct se_node_acl from the received Transport ID
3498 	 */
3499 	spin_lock_bh(&dest_se_tpg->acl_node_lock);
3500 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3501 				initiator_str);
3502 	if (dest_node_acl) {
3503 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3504 		smp_mb__after_atomic_inc();
3505 	}
3506 	spin_unlock_bh(&dest_se_tpg->acl_node_lock);
3507 
3508 	if (!dest_node_acl) {
3509 		pr_err("Unable to locate %s dest_node_acl for"
3510 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3511 			initiator_str);
3512 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3513 		goto out;
3514 	}
3515 	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
3516 	if (ret != 0) {
3517 		pr_err("core_scsi3_nodeacl_depend_item() for"
3518 			" dest_node_acl\n");
3519 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3520 		smp_mb__after_atomic_dec();
3521 		dest_node_acl = NULL;
3522 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3523 		goto out;
3524 	}
3525 #if 0
3526 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3527 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3528 		dest_node_acl->initiatorname);
3529 #endif
3530 	/*
3531 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3532 	 * PORT IDENTIFIER.
3533 	 */
3534 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3535 	if (!dest_se_deve) {
3536 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3537 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3538 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3539 		goto out;
3540 	}
3541 
3542 	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
3543 	if (ret < 0) {
3544 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3545 		atomic_dec(&dest_se_deve->pr_ref_count);
3546 		smp_mb__after_atomic_dec();
3547 		dest_se_deve = NULL;
3548 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3549 		goto out;
3550 	}
3551 #if 0
3552 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3553 		" ACL for dest_se_deve->mapped_lun: %u\n",
3554 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3555 		dest_se_deve->mapped_lun);
3556 #endif
3557 	/*
3558 	 * A persistent reservation needs to already existing in order to
3559 	 * successfully complete the REGISTER_AND_MOVE service action..
3560 	 */
3561 	spin_lock(&dev->dev_reservation_lock);
3562 	pr_res_holder = dev->dev_pr_res_holder;
3563 	if (!pr_res_holder) {
3564 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3565 			" currently held\n");
3566 		spin_unlock(&dev->dev_reservation_lock);
3567 		ret = PYX_TRANSPORT_INVALID_CDB_FIELD;
3568 		goto out;
3569 	}
3570 	/*
3571 	 * The received on I_T Nexus must be the reservation holder.
3572 	 *
3573 	 * From spc4r17 section 5.7.8  Table 50 --
3574 	 * 	Register behaviors for a REGISTER AND MOVE service action
3575 	 */
3576 	if (pr_res_holder != pr_reg) {
3577 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3578 			" Nexus is not reservation holder\n");
3579 		spin_unlock(&dev->dev_reservation_lock);
3580 		ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
3581 		goto out;
3582 	}
3583 	/*
3584 	 * From spc4r17 section 5.7.8: registering and moving reservation
3585 	 *
3586 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3587 	 * action is received and the established persistent reservation is a
3588 	 * Write Exclusive - All Registrants type or Exclusive Access -
3589 	 * All Registrants type reservation, then the command shall be completed
3590 	 * with RESERVATION CONFLICT status.
3591 	 */
3592 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3593 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3594 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3595 			" reservation for type: %s\n",
3596 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3597 		spin_unlock(&dev->dev_reservation_lock);
3598 		ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
3599 		goto out;
3600 	}
3601 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3602 	/*
3603 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3604 	 */
3605 	type = pr_res_holder->pr_res_type;
3606 	scope = pr_res_holder->pr_res_type;
3607 	/*
3608 	 * c) Associate the reservation key specified in the SERVICE ACTION
3609 	 *    RESERVATION KEY field with the I_T nexus specified as the
3610 	 *    destination of the register and move, where:
3611 	 *    A) The I_T nexus is specified by the TransportID and the
3612 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3613 	 *    B) Regardless of the TransportID format used, the association for
3614 	 *       the initiator port is based on either the initiator port name
3615 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3616 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3617 	 *       transport protocols where port names are not required;
3618 	 * d) Register the reservation key specified in the SERVICE ACTION
3619 	 *    RESERVATION KEY field;
3620 	 * e) Retain the reservation key specified in the SERVICE ACTION
3621 	 *    RESERVATION KEY field and associated information;
3622 	 *
3623 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3624 	 * register an I_T nexus that is already registered with the same
3625 	 * reservation key or a different reservation key.
3626 	 */
3627 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3628 					iport_ptr);
3629 	if (!dest_pr_reg) {
3630 		ret = core_scsi3_alloc_registration(cmd->se_dev,
3631 				dest_node_acl, dest_se_deve, iport_ptr,
3632 				sa_res_key, 0, aptpl, 2, 1);
3633 		if (ret != 0) {
3634 			spin_unlock(&dev->dev_reservation_lock);
3635 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3636 			goto out;
3637 		}
3638 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3639 						iport_ptr);
3640 		new_reg = 1;
3641 	}
3642 	/*
3643 	 * f) Release the persistent reservation for the persistent reservation
3644 	 *    holder (i.e., the I_T nexus on which the
3645 	 */
3646 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3647 			dev->dev_pr_res_holder, 0);
3648 	/*
3649 	 * g) Move the persistent reservation to the specified I_T nexus using
3650 	 *    the same scope and type as the persistent reservation released in
3651 	 *    item f); and
3652 	 */
3653 	dev->dev_pr_res_holder = dest_pr_reg;
3654 	dest_pr_reg->pr_res_holder = 1;
3655 	dest_pr_reg->pr_res_type = type;
3656 	pr_reg->pr_res_scope = scope;
3657 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3658 				PR_REG_ISID_ID_LEN);
3659 	/*
3660 	 * Increment PRGeneration for existing registrations..
3661 	 */
3662 	if (!new_reg)
3663 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3664 	spin_unlock(&dev->dev_reservation_lock);
3665 
3666 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3667 		" created new reservation holder TYPE: %s on object RTPI:"
3668 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3669 		core_scsi3_pr_dump_type(type), rtpi,
3670 		dest_pr_reg->pr_res_generation);
3671 	pr_debug("SPC-3 PR Successfully moved reservation from"
3672 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3673 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3674 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3675 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3676 		iport_ptr : "");
3677 	/*
3678 	 * It is now safe to release configfs group dependencies for destination
3679 	 * of Transport ID Initiator Device/Port Identifier
3680 	 */
3681 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3682 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3683 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3684 	/*
3685 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3686 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3687 	 */
3688 	if (unreg) {
3689 		spin_lock(&pr_tmpl->registration_lock);
3690 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3691 		spin_unlock(&pr_tmpl->registration_lock);
3692 	} else
3693 		core_scsi3_put_pr_reg(pr_reg);
3694 
3695 	/*
3696 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3697 	 * write out the updated metadata to struct file for this SCSI device.
3698 	 */
3699 	if (!aptpl) {
3700 		pr_tmpl->pr_aptpl_active = 0;
3701 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3702 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3703 				" REGISTER_AND_MOVE\n");
3704 	} else {
3705 		pr_tmpl->pr_aptpl_active = 1;
3706 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3707 				&dest_pr_reg->pr_aptpl_buf[0],
3708 				pr_tmpl->pr_aptpl_buf_len);
3709 		if (!ret)
3710 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3711 					" REGISTER_AND_MOVE\n");
3712 	}
3713 
3714 	transport_kunmap_first_data_page(cmd);
3715 
3716 	core_scsi3_put_pr_reg(dest_pr_reg);
3717 	return 0;
3718 out:
3719 	if (buf)
3720 		transport_kunmap_first_data_page(cmd);
3721 	if (dest_se_deve)
3722 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3723 	if (dest_node_acl)
3724 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3725 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3726 	core_scsi3_put_pr_reg(pr_reg);
3727 	return ret;
3728 }
3729 
3730 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3731 {
3732 	unsigned int __v1, __v2;
3733 
3734 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3735 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3736 
3737 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3738 }
3739 
3740 /*
3741  * See spc4r17 section 6.14 Table 170
3742  */
3743 static int core_scsi3_emulate_pr_out(struct se_cmd *cmd, unsigned char *cdb)
3744 {
3745 	unsigned char *buf;
3746 	u64 res_key, sa_res_key;
3747 	int sa, scope, type, aptpl;
3748 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3749 	/*
3750 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3751 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3752 	 */
3753 	if (!cmd->se_sess)
3754 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3755 
3756 	if (cmd->data_length < 24) {
3757 		pr_warn("SPC-PR: Received PR OUT parameter list"
3758 			" length too small: %u\n", cmd->data_length);
3759 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3760 	}
3761 	/*
3762 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3763 	 */
3764 	sa = (cdb[1] & 0x1f);
3765 	scope = (cdb[2] & 0xf0);
3766 	type = (cdb[2] & 0x0f);
3767 
3768 	buf = transport_kmap_first_data_page(cmd);
3769 	/*
3770 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3771 	 */
3772 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3773 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3774 	/*
3775 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3776 	 * SCSI TransportIDs.
3777 	 */
3778 	if (sa != PRO_REGISTER_AND_MOVE) {
3779 		spec_i_pt = (buf[20] & 0x08);
3780 		all_tg_pt = (buf[20] & 0x04);
3781 		aptpl = (buf[20] & 0x01);
3782 	} else {
3783 		aptpl = (buf[17] & 0x01);
3784 		unreg = (buf[17] & 0x02);
3785 	}
3786 	transport_kunmap_first_data_page(cmd);
3787 	buf = NULL;
3788 
3789 	/*
3790 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3791 	 */
3792 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3793 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3794 	/*
3795 	 * From spc4r17 section 6.14:
3796 	 *
3797 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3798 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3799 	 * the command shall be terminated with CHECK CONDITION status, with
3800 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3801 	 * code set to PARAMETER LIST LENGTH ERROR.
3802 	 */
3803 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3804 	    (cmd->data_length != 24)) {
3805 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3806 			" list length: %u\n", cmd->data_length);
3807 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3808 	}
3809 	/*
3810 	 * (core_scsi3_emulate_pro_* function parameters
3811 	 * are defined by spc4r17 Table 174:
3812 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3813 	 */
3814 	switch (sa) {
3815 	case PRO_REGISTER:
3816 		return core_scsi3_emulate_pro_register(cmd,
3817 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3818 	case PRO_RESERVE:
3819 		return core_scsi3_emulate_pro_reserve(cmd,
3820 			type, scope, res_key);
3821 	case PRO_RELEASE:
3822 		return core_scsi3_emulate_pro_release(cmd,
3823 			type, scope, res_key);
3824 	case PRO_CLEAR:
3825 		return core_scsi3_emulate_pro_clear(cmd, res_key);
3826 	case PRO_PREEMPT:
3827 		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
3828 					res_key, sa_res_key, 0);
3829 	case PRO_PREEMPT_AND_ABORT:
3830 		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
3831 					res_key, sa_res_key, 1);
3832 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3833 		return core_scsi3_emulate_pro_register(cmd,
3834 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3835 	case PRO_REGISTER_AND_MOVE:
3836 		return core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3837 				sa_res_key, aptpl, unreg);
3838 	default:
3839 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3840 			" action: 0x%02x\n", cdb[1] & 0x1f);
3841 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3842 	}
3843 
3844 	return PYX_TRANSPORT_INVALID_CDB_FIELD;
3845 }
3846 
3847 /*
3848  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3849  *
3850  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3851  */
3852 static int core_scsi3_pri_read_keys(struct se_cmd *cmd)
3853 {
3854 	struct se_device *se_dev = cmd->se_dev;
3855 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3856 	struct t10_pr_registration *pr_reg;
3857 	unsigned char *buf;
3858 	u32 add_len = 0, off = 8;
3859 
3860 	if (cmd->data_length < 8) {
3861 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3862 			" too small\n", cmd->data_length);
3863 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3864 	}
3865 
3866 	buf = transport_kmap_first_data_page(cmd);
3867 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3868 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3869 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3870 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3871 
3872 	spin_lock(&su_dev->t10_pr.registration_lock);
3873 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
3874 			pr_reg_list) {
3875 		/*
3876 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3877 		 * next reservation key list descriptor.
3878 		 */
3879 		if ((add_len + 8) > (cmd->data_length - 8))
3880 			break;
3881 
3882 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3883 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3884 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3885 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3886 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3887 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3888 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3889 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3890 
3891 		add_len += 8;
3892 	}
3893 	spin_unlock(&su_dev->t10_pr.registration_lock);
3894 
3895 	buf[4] = ((add_len >> 24) & 0xff);
3896 	buf[5] = ((add_len >> 16) & 0xff);
3897 	buf[6] = ((add_len >> 8) & 0xff);
3898 	buf[7] = (add_len & 0xff);
3899 
3900 	transport_kunmap_first_data_page(cmd);
3901 
3902 	return 0;
3903 }
3904 
3905 /*
3906  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3907  *
3908  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3909  */
3910 static int core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3911 {
3912 	struct se_device *se_dev = cmd->se_dev;
3913 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3914 	struct t10_pr_registration *pr_reg;
3915 	unsigned char *buf;
3916 	u64 pr_res_key;
3917 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3918 
3919 	if (cmd->data_length < 8) {
3920 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3921 			" too small\n", cmd->data_length);
3922 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3923 	}
3924 
3925 	buf = transport_kmap_first_data_page(cmd);
3926 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3927 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3928 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3929 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3930 
3931 	spin_lock(&se_dev->dev_reservation_lock);
3932 	pr_reg = se_dev->dev_pr_res_holder;
3933 	if ((pr_reg)) {
3934 		/*
3935 		 * Set the hardcoded Additional Length
3936 		 */
3937 		buf[4] = ((add_len >> 24) & 0xff);
3938 		buf[5] = ((add_len >> 16) & 0xff);
3939 		buf[6] = ((add_len >> 8) & 0xff);
3940 		buf[7] = (add_len & 0xff);
3941 
3942 		if (cmd->data_length < 22)
3943 			goto err;
3944 
3945 		/*
3946 		 * Set the Reservation key.
3947 		 *
3948 		 * From spc4r17, section 5.7.10:
3949 		 * A persistent reservation holder has its reservation key
3950 		 * returned in the parameter data from a PERSISTENT
3951 		 * RESERVE IN command with READ RESERVATION service action as
3952 		 * follows:
3953 		 * a) For a persistent reservation of the type Write Exclusive
3954 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3955 		 *      the reservation key shall be set to zero; or
3956 		 * b) For all other persistent reservation types, the
3957 		 *    reservation key shall be set to the registered
3958 		 *    reservation key for the I_T nexus that holds the
3959 		 *    persistent reservation.
3960 		 */
3961 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3962 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3963 			pr_res_key = 0;
3964 		else
3965 			pr_res_key = pr_reg->pr_res_key;
3966 
3967 		buf[8] = ((pr_res_key >> 56) & 0xff);
3968 		buf[9] = ((pr_res_key >> 48) & 0xff);
3969 		buf[10] = ((pr_res_key >> 40) & 0xff);
3970 		buf[11] = ((pr_res_key >> 32) & 0xff);
3971 		buf[12] = ((pr_res_key >> 24) & 0xff);
3972 		buf[13] = ((pr_res_key >> 16) & 0xff);
3973 		buf[14] = ((pr_res_key >> 8) & 0xff);
3974 		buf[15] = (pr_res_key & 0xff);
3975 		/*
3976 		 * Set the SCOPE and TYPE
3977 		 */
3978 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3979 			  (pr_reg->pr_res_type & 0x0f);
3980 	}
3981 
3982 err:
3983 	spin_unlock(&se_dev->dev_reservation_lock);
3984 	transport_kunmap_first_data_page(cmd);
3985 
3986 	return 0;
3987 }
3988 
3989 /*
3990  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3991  *
3992  * See spc4r17 section 6.13.4 Table 165
3993  */
3994 static int core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3995 {
3996 	struct se_device *dev = cmd->se_dev;
3997 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3998 	unsigned char *buf;
3999 	u16 add_len = 8; /* Hardcoded to 8. */
4000 
4001 	if (cmd->data_length < 6) {
4002 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
4003 			" %u too small\n", cmd->data_length);
4004 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4005 	}
4006 
4007 	buf = transport_kmap_first_data_page(cmd);
4008 
4009 	buf[0] = ((add_len << 8) & 0xff);
4010 	buf[1] = (add_len & 0xff);
4011 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
4012 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
4013 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
4014 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
4015 	/*
4016 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
4017 	 * set the TMV: Task Mask Valid bit.
4018 	 */
4019 	buf[3] |= 0x80;
4020 	/*
4021 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
4022 	 */
4023 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
4024 	/*
4025 	 * PTPL_A: Persistence across Target Power Loss Active bit
4026 	 */
4027 	if (pr_tmpl->pr_aptpl_active)
4028 		buf[3] |= 0x01;
4029 	/*
4030 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
4031 	 */
4032 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4033 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
4034 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
4035 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
4036 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
4037 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4038 
4039 	transport_kunmap_first_data_page(cmd);
4040 
4041 	return 0;
4042 }
4043 
4044 /*
4045  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4046  *
4047  * See spc4r17 section 6.13.5 Table 168 and 169
4048  */
4049 static int core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4050 {
4051 	struct se_device *se_dev = cmd->se_dev;
4052 	struct se_node_acl *se_nacl;
4053 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4054 	struct se_portal_group *se_tpg;
4055 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4056 	struct t10_reservation *pr_tmpl = &se_dev->se_sub_dev->t10_pr;
4057 	unsigned char *buf;
4058 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4059 	u32 off = 8; /* off into first Full Status descriptor */
4060 	int format_code = 0;
4061 
4062 	if (cmd->data_length < 8) {
4063 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4064 			" too small\n", cmd->data_length);
4065 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4066 	}
4067 
4068 	buf = transport_kmap_first_data_page(cmd);
4069 
4070 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4071 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4072 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4073 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4074 
4075 	spin_lock(&pr_tmpl->registration_lock);
4076 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4077 			&pr_tmpl->registration_list, pr_reg_list) {
4078 
4079 		se_nacl = pr_reg->pr_reg_nacl;
4080 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4081 		add_desc_len = 0;
4082 
4083 		atomic_inc(&pr_reg->pr_res_holders);
4084 		smp_mb__after_atomic_inc();
4085 		spin_unlock(&pr_tmpl->registration_lock);
4086 		/*
4087 		 * Determine expected length of $FABRIC_MOD specific
4088 		 * TransportID full status descriptor..
4089 		 */
4090 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4091 				se_tpg, se_nacl, pr_reg, &format_code);
4092 
4093 		if ((exp_desc_len + add_len) > cmd->data_length) {
4094 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4095 				" out of buffer: %d\n", cmd->data_length);
4096 			spin_lock(&pr_tmpl->registration_lock);
4097 			atomic_dec(&pr_reg->pr_res_holders);
4098 			smp_mb__after_atomic_dec();
4099 			break;
4100 		}
4101 		/*
4102 		 * Set RESERVATION KEY
4103 		 */
4104 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4105 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4106 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4107 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4108 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4109 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4110 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4111 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4112 		off += 4; /* Skip Over Reserved area */
4113 
4114 		/*
4115 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4116 		 */
4117 		if (pr_reg->pr_reg_all_tg_pt)
4118 			buf[off] = 0x02;
4119 		/*
4120 		 * The struct se_lun pointer will be present for the
4121 		 * reservation holder for PR_HOLDER bit.
4122 		 *
4123 		 * Also, if this registration is the reservation
4124 		 * holder, fill in SCOPE and TYPE in the next byte.
4125 		 */
4126 		if (pr_reg->pr_res_holder) {
4127 			buf[off++] |= 0x01;
4128 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4129 				     (pr_reg->pr_res_type & 0x0f);
4130 		} else
4131 			off += 2;
4132 
4133 		off += 4; /* Skip over reserved area */
4134 		/*
4135 		 * From spc4r17 6.3.15:
4136 		 *
4137 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4138 		 * IDENTIFIER field contains the relative port identifier (see
4139 		 * 3.1.120) of the target port that is part of the I_T nexus
4140 		 * described by this full status descriptor. If the ALL_TG_PT
4141 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4142 		 * IDENTIFIER field are not defined by this standard.
4143 		 */
4144 		if (!pr_reg->pr_reg_all_tg_pt) {
4145 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4146 
4147 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4148 			buf[off++] = (port->sep_rtpi & 0xff);
4149 		} else
4150 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFER */
4151 
4152 		/*
4153 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4154 		 */
4155 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4156 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4157 
4158 		spin_lock(&pr_tmpl->registration_lock);
4159 		atomic_dec(&pr_reg->pr_res_holders);
4160 		smp_mb__after_atomic_dec();
4161 		/*
4162 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4163 		 */
4164 		buf[off++] = ((desc_len >> 24) & 0xff);
4165 		buf[off++] = ((desc_len >> 16) & 0xff);
4166 		buf[off++] = ((desc_len >> 8) & 0xff);
4167 		buf[off++] = (desc_len & 0xff);
4168 		/*
4169 		 * Size of full desctipor header minus TransportID
4170 		 * containing $FABRIC_MOD specific) initiator device/port
4171 		 * WWN information.
4172 		 *
4173 		 *  See spc4r17 Section 6.13.5 Table 169
4174 		 */
4175 		add_desc_len = (24 + desc_len);
4176 
4177 		off += desc_len;
4178 		add_len += add_desc_len;
4179 	}
4180 	spin_unlock(&pr_tmpl->registration_lock);
4181 	/*
4182 	 * Set ADDITIONAL_LENGTH
4183 	 */
4184 	buf[4] = ((add_len >> 24) & 0xff);
4185 	buf[5] = ((add_len >> 16) & 0xff);
4186 	buf[6] = ((add_len >> 8) & 0xff);
4187 	buf[7] = (add_len & 0xff);
4188 
4189 	transport_kunmap_first_data_page(cmd);
4190 
4191 	return 0;
4192 }
4193 
4194 static int core_scsi3_emulate_pr_in(struct se_cmd *cmd, unsigned char *cdb)
4195 {
4196 	switch (cdb[1] & 0x1f) {
4197 	case PRI_READ_KEYS:
4198 		return core_scsi3_pri_read_keys(cmd);
4199 	case PRI_READ_RESERVATION:
4200 		return core_scsi3_pri_read_reservation(cmd);
4201 	case PRI_REPORT_CAPABILITIES:
4202 		return core_scsi3_pri_report_capabilities(cmd);
4203 	case PRI_READ_FULL_STATUS:
4204 		return core_scsi3_pri_read_full_status(cmd);
4205 	default:
4206 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4207 			" action: 0x%02x\n", cdb[1] & 0x1f);
4208 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4209 	}
4210 
4211 }
4212 
4213 int core_scsi3_emulate_pr(struct se_cmd *cmd)
4214 {
4215 	unsigned char *cdb = &cmd->t_task_cdb[0];
4216 	struct se_device *dev = cmd->se_dev;
4217 	/*
4218 	 * Following spc2r20 5.5.1 Reservations overview:
4219 	 *
4220 	 * If a logical unit has been reserved by any RESERVE command and is
4221 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4222 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4223 	 * initiator or service action and shall terminate with a RESERVATION
4224 	 * CONFLICT status.
4225 	 */
4226 	if (dev->dev_flags & DF_SPC2_RESERVATIONS) {
4227 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4228 			" SPC-2 reservation is held, returning"
4229 			" RESERVATION_CONFLICT\n");
4230 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
4231 	}
4232 
4233 	return (cdb[0] == PERSISTENT_RESERVE_OUT) ?
4234 	       core_scsi3_emulate_pr_out(cmd, cdb) :
4235 	       core_scsi3_emulate_pr_in(cmd, cdb);
4236 }
4237 
4238 static int core_pt_reservation_check(struct se_cmd *cmd, u32 *pr_res_type)
4239 {
4240 	return 0;
4241 }
4242 
4243 static int core_pt_seq_non_holder(
4244 	struct se_cmd *cmd,
4245 	unsigned char *cdb,
4246 	u32 pr_reg_type)
4247 {
4248 	return 0;
4249 }
4250 
4251 int core_setup_reservations(struct se_device *dev, int force_pt)
4252 {
4253 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
4254 	struct t10_reservation *rest = &su_dev->t10_pr;
4255 	/*
4256 	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
4257 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
4258 	 * cause a problem because libata and some SATA RAID HBAs appear
4259 	 * under Linux/SCSI, but to emulate reservations themselves.
4260 	 */
4261 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
4262 	    !(dev->se_sub_dev->se_dev_attrib.emulate_reservations)) || force_pt) {
4263 		rest->res_type = SPC_PASSTHROUGH;
4264 		rest->pr_ops.t10_reservation_check = &core_pt_reservation_check;
4265 		rest->pr_ops.t10_seq_non_holder = &core_pt_seq_non_holder;
4266 		pr_debug("%s: Using SPC_PASSTHROUGH, no reservation"
4267 			" emulation\n", dev->transport->name);
4268 		return 0;
4269 	}
4270 	/*
4271 	 * If SPC-3 or above is reported by real or emulated struct se_device,
4272 	 * use emulated Persistent Reservations.
4273 	 */
4274 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
4275 		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
4276 		rest->pr_ops.t10_reservation_check = &core_scsi3_pr_reservation_check;
4277 		rest->pr_ops.t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
4278 		pr_debug("%s: Using SPC3_PERSISTENT_RESERVATIONS"
4279 			" emulation\n", dev->transport->name);
4280 	} else {
4281 		rest->res_type = SPC2_RESERVATIONS;
4282 		rest->pr_ops.t10_reservation_check = &core_scsi2_reservation_check;
4283 		rest->pr_ops.t10_seq_non_holder =
4284 				&core_scsi2_reservation_seq_non_holder;
4285 		pr_debug("%s: Using SPC2_RESERVATIONS emulation\n",
4286 			dev->transport->name);
4287 	}
4288 
4289 	return 0;
4290 }
4291